Introduction

A nation’s armed forces reflect its geography, presumed threats, wealth, culture and traditions. Changes over time alter some factors; others stay relatively constant. Such is surely the case with the U.S. Army, one of the oldest, most celebrated national institutions and a central player in the American story. As a military organization in a Western-oriented republic, it takes much from European precedents and practices, but it also draws from American circumstances. The country’s vast spaces, abundant natural resources and lack of major security threats on its borders—as well as its individualized society, frontier heritage and increasingly diverse population—have shaped its military establishment, including its historical reliance on a sizable reserve component to accompany a professional, regular force. At the same time, technology and a shrinking world have changed perceptions of national security and the Army’s contribution to it. The rise to superpower status and the expansion of national interests to a global scale have added to the Army’s role and responsibilities, presenting a spectrum of potential conflicts in which the most dangerous contingencies are not necessarily the most likely, but for all of which the Army must prepare. And it does so under the nuclear specter, an existential danger that constrains the full use of American power.

The Militia Versus the Standing Army; 1607–1815

Origins of the U.S. Army

The dangers facing isolated communities during the early years of English settlement of the New World may not have reached the scale of weapons of mass destruction, but they were real enough. A long land frontier and extended coastline, a sparse and dispersed population, political disunity and a distant imperial government left numerous points vulnerable to attack from land and sea. The 17th century was an era of great imperial rivalry; colonists had to prepare for attacks from the Spanish, from the Dutch, and, later, from the French. Native Americans also presented a potential threat. Although European-introduced epidemics and alcohol, loss of farming and hunting grounds, and the slave trade largely decimated the eastern woodland nations, they were still key players in the international system, particularly as the fur trade grew in importance. For the natives, war could involve property destruction, ritual torture and killing of noncombatants to displace territorial rivals and gain revenge or tribute, but it also featured cultural restraints, avoiding heavy casualties and taking prisoners for prestige or adoption and replenishment of native populations. By 1650, many Indians possessed muskets and—in several cases—were more skilled in their use than were the colonists. Although some nations adopted fortifications, native tactics mostly involved raids, mobility, stealth and surprise, cutting off and attacking isolated settlements and ambushing columns passing through the dense forests. Early colonists also faced internal threats from dissidents, criminals and revolts by enslaved peoples.

Following their colonial charters, the settlers turned to an old English institution: the militia. Every able-bodied male, excepting clergy and a few other exemptions, was liable for service and was supposed to supply his own firearm and ammunition. Some Blacks and natives served in the early days, but by 1774, most colonies south of New England prohibited their participation. A few professional officers, such as John Smith of Jamestown and Myles Standish of Plymouth, might provide guidance and oversee periodic musters, but training days were generally too few to instill more than a basic competence. Different systems emerged. In the Chesapeake region, with its plantation economy, the colonies formed companies from the inhabitants of a given area. Each town in more densely populated New England formed one or more companies soon after forming local governments. In South Carolina, with its rice plantations and majority of Blacks, the militia primarily repressed slave revolts. When the frontier moved west, the system followed it, as the backcountry relied on local militia to maintain order. Even when the British Army eventually built forts in the interior, those posts were often so undermanned and poorly supplied that they depended on the local population just to survive.

Over time, colonial society became more prosperous, stratified and diverse. A growing population, mostly farmers, tended the abundant arable land and teeming offshore fisheries. Along the coast and navigable rivers, plantations, towns and a few cities traded and evolved a more status-conscious society in which rich elites identified closely with Europe and expected deference from lower sorts. By the early 1770s, the colonial population had reached 2.5 million, including 540,000 mostly enslaved African Americans. Two-thirds of the White colonists owned land. Highly religious, most were Protestant Christians, many influenced by the evangelical Great Awakening of the 1740s. Militant Puritanism, with its martial sermons on war and the Old Testament, dominated New England. In contrast, the pacifist Society of Friends initially settled Pennsylvania, but as other ethnic and religious groups arrived, conflicts arose between the Quaker governing elite and newcomers over defense of the colony, leading non-pacifists, such as Benjamin Franklin, to form a voluntary military association in 1747. As alluded to earlier, by 1775, disease, warfare, dispossession and enslavement had eradicated or reduced the indigenous nations east of the Mississippi to about 250,000 people and disrupted their societies. Some natives had become more integrated into the larger political economy through the frontier’s “Middle Ground” of cultural and material contact; others struggled to maintain a distinct cultural identity. While many Whites saw them as uncivilized, the more cosmopolitan viewed them as an isolated branch of the human family at an earlier developmental stage, capable of improvement, with no essential human difference.

Whatever this ambivalence and the transactional relations of the Middle Ground, Indian wars were vicious, cultural conflicts. Many of the early settlers had experienced the harsh European religious wars and were predisposed to view the natives as inferior beings or Satan’s minions, even where conflicts boiled down to competition for land and trade. Given the North American environment and logistical limitations, most operations on both sides consisted of small-scale patrols, raids and surprise attacks, not sustained combat. At first, English muskets and disciplined firing overpowered bows and arrows, beating off Indian attacks from well-fortified garrison houses. When militia conducted expeditions into the wilderness in search of elusive war parties, however, deficiencies in field craft and military discipline became apparent. Over time, the colonists capitalized on divisions between the nations and relied on Indian allies to guide them. Frequently, colonists resolved conflicts by burning native villages and crops, using deprivation as a tool to break their will to fight. The brutality extended to bounties for the scalps of hostile Indians and even rare efforts to transmit smallpox to the natives. In the end, indigenous economies and societies lacked the ability to sustain a long war—unless they were aided by a European ally that provided arms, supplies, sanctuaries and, on occasion, advisers.

Moreover, by the late 17th century, the English colonists were relying less on the general militia and more on volunteers, levies and specialists. Mobilization of a town’s or a county’s entire male population for a long period could have dire economic consequences, and dispersed settlement patterns made the task even harder. Colonial governments recruited regiments and battalions for a single campaign or a year, relying first on volunteers and incentives. At times, local committees drafted individuals, tending toward those who were young, unmarried, unemployed or vagrants. However, the lower classes could, and did, refuse to serve in what seemed rich men’s wars, and the elites soon found that a force of well-paid volunteers was preferable to coercion. But even these detachments could disrupt community life, especially if service extended to long stints at isolated outposts. Officials often hired specialists—such as Colonel Benjamin Church’s rangers—to conduct long-range raids. Others patrolled the vast spaces between posts, taking scalps and prisoners, gathering information and providing early warnings. But they never had enough funds, troops or forts to entirely secure the frontier. During the imperial conflicts of 1689–1748, governors and legislators recruited volunteers and appointed officers for expeditionary forces that mimicked the structure of regular British units. In 1745, New England provincials took the strategically significant French fortress of Louisbourg. Many colonists accumulated several years of service, and men such as Colonel George Washington and Captain Philip Schuyler emulated British regular officers by reading Humphrey Bland’s A Treatise of Military Discipline and other military literature.

Although often experienced in Indian war tactics, European-oriented elites such as Washington were more culturally inclined toward the limited, conventional conflicts for trade, colonies and land characteristic of European wars of the era. Reacting against the horrors of the religious wars, European monarchs of the 18th century fought “just wars” that employed restraint while still using war as an instrument of policy. Still, the imperial wars in North America generally continued the pattern of small-scale raids, except for sporadic maritime expeditions against New France or Spanish possessions. Up to 1755, the British Crown provided relatively little support beyond some warships, money and supplies. The war of 1754–1763—known in America as the French and Indian War—was different. Both Great Britain and France deployed to North America large regular armies that fought conventional battles and sieges but also introduced light and partisan tactics on a limited scale. Except for special units like Rogers’ Rangers, which followed European doctrine, provincial formations usually did support missions of screening, logistics, local defense and other tasks. With control of the sea, adequate logistical support and communications, superior numbers and a skillful offensive strategy, the British finally captured Fort Duquesne in western Pennsylvania and forced their way up Lake Champlain and the St. Lawrence River into the heart of French power at Quebec and Montreal. The Treaty of Paris of 1763 at last removed the French and Spanish presence from the colonies’ northern and southern frontiers.

Among many colonists, contact with British regulars during the war confirmed their animus against “standing armies,” an Anglo-American distrust fed by the memory of the excesses of Oliver Cromwell’s New Model Army of the 1650s. Already distrustful of centralized power, colonists resented being automatically outranked by their British counterparts, and they dismissed British soldiers as corrupt, robotic hirelings, naturally inferior to the virtuous, unspoiled, free men who had carved homes out of the American wilderness. To these citizen soldiers, military service was a contractual obligation that came with their individual rights. Cases like Major General Edward Braddock’s 1755 debacle on the way to Fort Duquesne only validated their low opinions of British fighting abilities—and the contempt of regular British officers for provincials did nothing to improve the latter’s views of the former. British recruiting and impressment of food, quarters and transportation raised tensions. When Parliament imposed new taxes in part to support a new, sizable British military establishment for North America, the colonists responded that their militia was more than adequate for local defense and wondered whether such a large force might have a darker, more oppressive motive. Nor were they completely wrong in their views. In Massachusetts, about one-third of the militia had taken part in the previous war, and many of the best veterans provided leadership for the “minute companies” of younger, enthusiastic, single men, trained at frequent rigorous musters and ready to spring to arms on short notice. It is notable that these early companies did not bar people of color in 1775, nor did they distinguish between enslaved and free men.

The Revolutionary War

Thus, when the “minutemen” clashed with British regulars at Lexington and Concord, the colonists responded by forming provisional armies to fight for American rights within the Empire. The “Army of Observation” that blockaded Boston consisted of separate contingents from the New England colonies, each drawing on its militia pool for recruits, and united by a committee form of leadership. Despite its loose command structure, this force performed creditably at Bunker Hill. But New England wanted participation from the other colonies, and on 14 June 1775, the Second Continental Congress in Philadelphia adopted the Army of Observation and added 10 companies of riflemen to form the new Continental Army. The next day, it chose George Washington as General and Commander in Chief. The presence, if temporary, of a conventional army with a European orientation reflected the delegates’ belief that such a force was preferable to reliance on a militia that would conduct guerrilla warfare, the alternative advocated by some former British officers such as Charles Lee. Still, the modest size of the Continental Army and its short-term enlistments reflected widespread suspicion of a standing army and the colonial heritage of temporary expeditionary forces. The Rage Militaire that pervaded colonial society—abetted by a militant clergy that portrayed the colonies as God’s virtuous chosen nation in a righteous battle with tyranny—stimulated recruiting throughout the colonies. But for all the enthusiasm, few Continental regiments reached full strength, and the Army, still an egalitarian New England mass with a loose discipline that offended its Virginian patrician leader, was due to disband at year’s end.

Over the course of 1776, the need for a more permanent force became apparent. In July, the Declaration of Independence changed the patriot objective from defense of American rights to national survival. The turmoil surrounding the re-creation of new armies at the end of 1775 and 1776, along with the poor performance of the existing Army—and especially the militia—in conventional battles in Canada and around New York, drove home the need for a longer-term, more disciplined force. Consequently, in early 1777, the states began to recruit troops either for three years or for the duration of the conflict. Longer service gradually changed the Army’s composition from middling part-timers to more marginal elements of society: younger sons, small farmers, African Americans, Indians and poorer transient elements who enlisted for bounties, land grants and steady work. They were supported by “camp followers”—sutlers, contractors and women who served as laundresses, nurses and sometimes as cooks. Under Washington, a mostly conventional soldier, the army evolved with training, discipline and experience, developing an officer corps that, while sensitive on points of honor and their status, represented a rough meritocracy. They were aided by a wave of foreign volunteers who improved the army’s professionalism. Major General Louis le Bègue de Presle Duportail and Colonel Andrew Thaddeus Kosciuszko raised the expertise of the engineers, while Major General Friedrich Wilhelm von Steuben standardized training after his arrival during the dismal Valley Forge winter of 1777–1778. He eventually served as Inspector General. A young French nobleman, the Marquis de Lafayette, became one of Washington’s most trusted officers.

Even with these improvements, the Continental Army could never force a decision by annihilating the main British army on the battlefield. While Washington preferred aggressive tactics wherever possible, he found himself reduced to a strategy of exhaustion, keeping his Army in the field long enough for the British to tire of the struggle. He maneuvered to deny vital points to the British, fighting defensive battles where necessary, but increasingly avoided putting his force at risk. Fortunately, the American continent presented few vital points essential to the nation’s war effort. Even the capture of Philadelphia in the fall of 1777 did little lasting damage to the cause. Yet, Washington needed some victories to maintain morale and the legitimacy of patriot governments. The small successes of Trenton and Princeton in late 1776 and early 1777 raised morale and encouraged reenlistments, and the battles of Brandywine and Germantown in the fall of 1777, while defeats, showed foreign observers the Army’s competence and resilience. Although militia contributed little in major battles and could not operate far from their homes for long periods, they played a critical role in population and resource control. They provided local security, gathered intelligence, raided posts, harassed foraging parties, suppressed loyalists and limited British authority to areas actually occupied by the redcoats. Thus, the British remained frustrated in their attempts to suppress the Revolution, as evidenced in October 1777, when Lieutenant General John Burgoyne’s Anglo-German army, cut off by Continentals and militia in upstate New York, surrendered at Saratoga. It was the final step of bringing France into the war on the American side.

With the entry of France—and later Spain and the Netherlands—the war became a global conflict in which North America was no longer the primary theater. After the indecisive battle of Monmouth in June 1778, the main armies settled into a stalemate around New York, skirmishing in Westchester, the Hudson Highlands and New Jersey. The Continental Army, the physical and psychological core of the Revolution, built vital housing, depots and fortifications in the region and further developed its competence, but Washington needed a French fleet and army to attack New York. The practices of 18th-century warfare among the Anglo-Americans contrasted with the vicious struggle against the loyalists and British-allied Indians, including four of the Six Nations, whose crops and villages were destroyed by patriot expeditions. When the British took the offensive in the South to capitalize on loyalist support there, they touched off a brutal civil war that pitted neighbors against each other in the Carolina backcountry. Capture of an American army at Charleston in May 1780 and defeat at Camden in August dropped American morale to a new low. Soaring inflation left Congress dependent on French monetary aid, and the states struggled to produce supplies, weapons and soldiers as citizens resisted conscription. Continental troops mutinied over lack of pay. Once again, the patriots needed victories. And in 1781, they turned the tide. Brilliant coordination of partisans and Continentals by Major General Nathanael Greene recovered almost all of the Carolinas and Georgia. In the fall, Washington obtained the French fleet and army he needed to force Lieutenant General Charles Earl Cornwallis’ surrender at Yorktown, Virginia.

During the ensuing two years, as American envoys negotiated French support in Paris, the Continental Army made another enormous contribution to the new nation. As the British threat receded, a weak, destitute Congress and fledgling state governments struggled to maintain unity and order; to a major degree, the Army was the nation. Poorly paid with uncertain prospects, the Army felt neglected by civilian society, and talk of mutiny again rumbled through the force. Washington’s role was crucial. The Commander in Chief had always been important as both a political and military figure, living up to popular ideals of true patriotism by renouncing pay and conspicuously deferring to civilian authority. As part of the conservative elite, he had moderated the impulse toward a destructive people’s war. Now, while recognizing that his soldiers were at the limits of their endurance, he promoted Congressional supremacy. When creditors and some nationalist delegates encouraged angry Continental officers toward military intervention that would force the grant of taxation power to Congress, Washington called a meeting at the Army’s encampment at Newburgh, New York, warned the audience that a coup would open the way to civil discord and emotionally recalled the sacrifices they had made in the common cause. The “Newburgh Conspiracy” collapsed, and the officers reaffirmed their loyalty to Congress, which pledged five years of full pay as a pension. Washington confirmed civilian supremacy by personally returning his commission to Congress in late December 1783. With peace, Congress discharged the Army. By June 1784, only 80 troops remained, and they guarded military stores at West Point and Fort Pitt.

Federalists Versus Jeffersonians

What kind of military force would the new republic need? The fledgling nation had the advantage of distance from Europe and the intervening oceans, but security still rested mostly on good relations with British Canada and the Spanish Empire, which controlled the key port of New Orleans, Florida, and the land west of the Mississippi. The national government under the Articles of Confederation remained weak, and localist American society distrusted centralized power. Nationalists believed that external threats and internal disorders required a regular military establishment, and Washington proposed a small regular force to man forts, a “well organized militia,” a few arsenals and academies. But the nationalists’ opponents contended that a regular army would only lead to despotism and that reliance on state militia for brief service periods was sufficient. Their mythology of the Revolution stressed the role of the individual marksman, natural American fighters unfettered by conventional military training, over any professional institution. For the moment, in June 1784, Congress asked Pennsylvania, Connecticut, New York and New Jersey to provide militiamen for eight infantry and two artillery companies, around 700 men, for a year’s service. Recruiting was slow, with only Pennsylvania and New Jersey meeting their quotas; in April 1785, Congress called for the direct enlistment of 700 men for three years. This tiny force could not effectively carry out its mission of showing the flag and controlling the settlers who were flooding beyond the Appalachians.

 When the Constitutional Convention met in Philadelphia in 1787, delegates recognized the need for a more permanent military establishment. The new Constitution allowed for a national regular army and navy and a militia under state control, but it took pains to keep those forces under tight civilian rein, providing for congressional control of appropriations and designating the president as commander in chief of regular forces and of the militia when called into federal service to enforce the laws of the Union, put down insurrections and repel invasions. Congress had the power to organize, arm and discipline state militia, but states kept the right to appoint officers and train the militia in the discipline prescribed by Congress. Similar to the British precedent, Congress could only appropriate money for the military for two years, another safeguard against the standing army. An amendment enshrining the right to bear arms reinforced the militia. Yet, the Constitution gave the federal government almost unlimited ability to recruit and maintain armies and extensive powers to tax and pay for them. In addition, an officer’s oath of allegiance to the Constitution safeguarded subordination to civilian leadership.

On the basis of this constitutional experiment, yet with a still unsettled sense of national identity, the new nation and its Army confronted a troubled world. The French Revolution and Napoleonic Wars were overturning Europe’s old order as Britain and its allies struggled to contain France. The Royal Navy’s blockade and French privateers infringed on American neutral rights, and the Barbary pirates seized American ships and crews in the Mediterranean, two threats that primarily involved the new Navy. In the Old Northwest, the British still occupied forts they had promised to surrender in the peace treaty. Internally, the not-so-United States was riven by political divisions exacerbated by attachments to the opposing sides in Europe. Conservative Federalists identified with the British, while more radical Republicans were inspired by revolutionary France. Such divisions, with all the resulting paranoia, rancor and charges of infidelity to the legacy of the Revolution, complicated the task of consolidating the new central government and its authority over a far-flung territory. The early Regular Army was not much of a force and was little regarded in society. It took its enlisted ranks from those in the lower classes, who could not find jobs elsewhere. Many officers drew their commissions from political patronage and personal relationships, drank and feuded too much, and showed little motivation to develop themselves professionally. Even with some Revolutionary veterans, the poorly trained, dispersed force was in no position to meet European regulars on equal terms.

From 1789 to 1801, the Federalist administrations of Washington and John Adams implemented the Constitution’s military provisions. Federalists were realists who saw war as innate to the world system and as an instrument of policy, to be used with reason and restraint. They wanted a small but professional regular army that could both project power and command respect. The militia they viewed mainly as an instrument of social control and a moral school to teach industry, patriotism and deference, not as a reliable organization for defense. The Militia Act of 1792 provided for all able-bodied men, ages 18–45, to serve in the enrolled militia, but Congress set aside no funds to support the institution. When, in 1794, farmers in western Pennsylvania rebelled against a federal excise tax on liquor and stills, Washington called up 15,000 militia from Pennsylvania and nearby states to suppress the Whiskey Rebellion. As for the regulars, Congress authorized construction of coastal defense forts, but most troops served on isolated frontier posts where life was dull, discipline rigid, drunkenness common and desertion rampant.

For a fleeting moment, the regulars experienced a renaissance. On the frontier, Federalist policies stressed patience and assimilation of the Indians, but the Army could not restrain the flow of settlers into the Ohio Country. When peace talks stalled, two successive expeditions by regulars and militia failed. The latter, in which skillful native tactics surprised and overwhelmed Major General Arthur St. Clair’s 1,400 men in November 1791, was especially humiliating, and critics blamed poor leadership and unruly militia. Major General Anthony Wayne took command and ensured that his new 3,000-man Legion—an innovative formation that closely integrated regular infantry, skirmishers, light artillery and dragoons—had rigorous training and discipline. At Fallen Timbers in August 1794, his bayonet charge inflicted a stinging defeat on the Indians, who had to cede their Ohio lands. Yet Congress dissolved the Legion, returning to a tiny regular force to save money. When war with France threatened in 1798, Congress authorized a Provisional Army, which Alexander Hamilton tried to turn into a Federalist sinecure that would keep domestic order, repel invasion and even seize Spanish territory. But Adams’ peace with France in 1800 forced the disbandment of this half-raised force, leaving 3,400 regulars.

Thomas Jefferson came to office in 1801 with sharply ambivalent views toward the military. He would have liked to rely for defense on a militia of virtuous citizens who supposedly had won the Revolution. He was philosophically opposed to a regular army in peacetime, viewing it as expensive and a danger to individual liberties. He sought peaceful resolution of international disputes through negotiation, resorting to economic coercion where talks failed. But he was also prepared to use war as an instrument of policy, employed in the interests of justice and human progress; thus, as a practical matter, he accepted the need for a permanent regular force. Deeply concerned about a disloyal Army, he purged several Federalists from the officer corps and inserted strong Republicans in their places, further factionalizing the force. To cut expenses, he gutted the Army’s fledgling supply organization. But he did create the U.S. Military Academy in 1802 to provide the Army—and society—with trained engineers. He also incorporated the Army into his dream of national expansion. After purchasing the Louisiana Territory in 1803, he sent the Lewis and Clark expedition to explore the vast new domain. Other Army expeditions mapped the West, and federal troops built new forts and roads across the expanding frontier. For all of his interest in their culture, Jefferson saw the Indians as backward savages, and the rise of Tecumseh’s Confederacy confirmed Jeffersonian suspicions of British designs in the Old Northwest. Governor William H. Harrison’s costly victory at Tippecanoe in November 1811 reduced but did not eliminate this threat.

When a second war with Britain finally came in June 1812, the Army was poorly prepared and performed accordingly. The Regular Army contained only 6,700 men, and the nation relied heavily on the militia and on volunteers, which governors raised at presidential call. Born of frustration over the inability of embargoes to enforce neutral rights in the Napoleonic Wars, the conflict involved successive campaigns to conquer Canada and remove, once and for all, the threat of British support for the Indians. Many Republicans shared Jefferson’s view that the conquest of Canada would be “a mere matter of marching.” But they did little to improve militia training or administration before the war. When war came, James Madison’s administration, concerned almost as much about the growth of federal power in wartime as any danger from the British, took a minimalist approach to fighting the conflict. The Army tried to invade Canada from Detroit, the Niagara region and the Lake Champlain corridor, but all three invasions faltered due to logistical problems, incompetent and fractious commanders, and the refusal on valid constitutional grounds by the militia—especially from anti-war, Federalist New England—to cross into Canada. Despite isolated successes by especially well-led militia units, the federal government lost confidence in the mostly undisciplined, apathetic, ill-equipped, part-time soldiers—and the regulars, themselves poorly led and trained, did little better. By the spring of 1814, the federal government was essentially bankrupt, and the fall of Napoleon in Europe freed thousands of British regulars for service in North America. If not for some isolated naval victories, national morale would have reached a new low.

Late victories rescued the U.S. Army from total ignominy but still left the country with a mixed verdict on its military institutions. Reorganization, better recruiting and training, and an influx of tough, able commanders who knew how to lead citizen soldiers finally showed results in the war’s last desperate year. In late 1813, an American naval triumph on Lake Erie enabled Harrison, now a major general, to penetrate Canada with a mostly militia army, kill Tecumseh, and shatter his Confederacy at the battle of the Thames. At Chippewa and Lundy’s Lane in July 1814, American soldiers, who had been rigorously drilled by Brigadier General Winfield Scott and led by Major General Jacob J. Brown, fought so well that a British general allegedly exclaimed, “Those are Regulars, by God!” After a British raid burned Washington, the stout defense of Baltimore and Fort McHenry by Maryland militia and regular artillery inspired a nation and moved Francis Scott Key to write “The Star-Spangled Banner.” Yet, no battle did more to arouse American pride and patriotism than Major General Andrew Jackson’s crushing victory over Britain’s Napoleonic veterans at New Orleans. Even though it came in January 1815, after envoys had already signed the peace treaty in distant Belgium, the triumph of Jackson’s motley army, combining a few regular infantry units, Kentucky and Tennessee militia, Free Men of Color and Jean Lafitte’s pirates, restored national confidence and made Jackson a national hero. New Orleans better fit the Jeffersonian idea of the citizen soldier as the backbone of national defense, but the regulars also emerged from the war with more respect, as Republicans moderated their antipathy toward a standing army in peacetime.

The Frontier Constabulary and Volunteers; 1815–1890

Manifest Destiny

Historians have often labeled the 19th century after the War of 1812 as “The Age of Free Security,” when the United States faced minimal external threats and could focus on internal development and continental expansion. In the 1820s, this was not so clear. Memories of the War of 1812 were still fresh, and they motivated a rush to improve coastal fortifications. Great Britain remained in Canada, although Anglo-American relations gradually warmed as diplomacy resolved the issues and occasional crises between the two countries. For a time, the danger of European interference in the Latin American wars of independence aroused concern, but President James Monroe’s warning against further European interference in the affairs of the Western Hemisphere, and, more likely, the protecting shield of the Royal Navy, deterred intervention.

Behind that shield, the United States grew in size and power, animated by Manifest Destiny, a sense of mission to span the American continent. The market revolution—with its business cycles; industrialization; development of roads, canals and railroads; and sectional and ideological divisions over slavery, internal improvements, tariffs, land policy and the nature of the republic—consumed the turbulent young nation. Politically, it was the Age of Jackson, whose rags-to-riches story inspired the rise of democracy, rugged individualism and anti-elitism of the emerging capitalist society. Popular culture sang the virtues of the common man even as the Industrial Revolution instituted regimentation and discipline in its burgeoning factories. The spirit of the age ran against the intellectual and concrete, and more toward intangibles like courage, will, faith, intuition and natural genius. Martial manhood glorified physical strength, bravery, violence and domination, as an adventurous generation moved west in search of liberating emotional experience and personal transformation, pushing aside those in their way. In this era of romantic nationalism, all American wars seemed defensive and continental expansion beneficent, since the United States, by definition, was a virtuous, peaceable republic. Romanticism showed its darker side in growing racial, ethnic and religious bigotry toward immigrants, Indians and African Americans.

One of the few national institutions in this young republic of great size, small government and widely dispersed population was the U.S. Army. In an egalitarian age, officers still endured widespread disdain as aristocrats, martinets and dandies, but they also earned acceptance for their increasing professionalism. In the 1820s, Secretary of War John C. Calhoun reorganized the War Department bureaus to raise their efficiency, and Major Sylvanus Thayer turned the Military Academy at West Point into a respected institution for producing officers. Those graduates, who filled almost the entire officer corps of a Regular Army that rarely exceeded 10,000 men, stood mostly apart from politics and gave more thought to professional topics. Finding Indian conflicts distasteful distractions, they preferred to prepare for conventional warfare against a European foe. In line with the Academy’s emphasis, many rejected the popular attitude that military success resulted from natural genius and instead saw war as a science, an engineering project conducted by skilled technicians according to certain principles. French ideas and tactics were especially influential. The West Point faculty, including several French military advisers, emphasized staff processes, engineering and fortification, largely for the purpose of training officers to build Atlantic coastal defenses. They resisted teaching history and literature until the 1850s, and only then to illustrate military science. A few intellectuals, such as Dennis Hart Mahan and Henry W. Halleck, considered strategy, though Halleck focused on the methodical and almost mathematical seizure of strategic points.

The Army played a major role in Jacksonian America. It constructed an integrated system of large, masonry forts to protect key harbors, to force blockading ships further offshore and to guard the best invasion routes. But Americans also expected the service to go beyond strictly military tasks and to contribute to national growth, especially in the development of infrastructure. Army engineers surveyed for roads, canals and railroads, they built lighthouses, aqueducts and bridges, and they assisted with harbor and river improvements. In the young nation’s capital of Washington, DC, they constructed the Capitol dome, the Washington Monument and the Smithsonian’s main edifice. Arsenals in Springfield, Massachusetts, in Philadelphia and in Harper’s Ferry, Virginia, helped spark the Industrial Revolution with their use of interchangeable parts in arms manufacture. Army doctors added to medical knowledge through research on smallpox vaccination and on digestion. As sectional tensions rose, the Army bolstered federal authority in South Carolina during the Nullification Crisis of 1832, but it also helped enforce the Fugitive Slave Law in the 1850s. These sporadic diversions aside, Army personnel stationed at the War Department, arsenals, depots or coastal garrisons lived fairly pleasant lives.

The same did not hold true for line units on isolated frontier posts. Focused on constabulary and garrison duties, these officers had little time for the study of war, which many saw as influenced more by genius and intangible moral forces than by education and scientific principles. Enlisted men—mostly immigrants or youths seeking adventure or escape from home—endured considerable manual labor, constructing forts and roads under harsh regular discipline. All faced hardship, disease, bad rations and poor living quarters. The Army on the frontier explored, studied flora and fauna, surveyed routes for a future transcontinental railroad, served as relief workers in natural disasters, provided medical aid and enforced order. In the 1850s, it intervened in the strife between free- and slave-state settlers in Bleeding Kansas, and it carried out an expedition to Utah when the Mormons openly challenged federal authority. And, of course, it dealt with Indians, mediating disputes between natives and settlers. When, in the 1830s, President Jackson ordered the removal of eastern tribes to present-day Oklahoma, many officers sympathized with the Indians’ plight and sought to ameliorate some of the worst effects.

Whatever its sympathies, the Army reverted to many old practices when Indians resisted the nation’s expansion. Although oriented toward conventional warfare, the service adapted its organization, equipment and transport for harsh frontier conditions. It employed indigenous scouts and learned to use local sources to determine the size and composition of war bands. In the Plains, the Army introduced more cavalry to counter the highly mobile warriors. But when the Army failed to pin down the elusive natives, it reverted to colonial methods of destroying foodstuffs and shelter, not so much as a plan for genocide but as a strategy of attrition or exhaustion. The Seminole Wars, in particular, tested the Army’s ability to deal with heat, humidity, rugged terrain and skillful native guerrilla tactics. Columns of soldiers trudged through the Florida swamps, searching for Seminole camps and supplies and finding few. In frustration, some employed false flags of truce and committed atrocities. Commanders turned to area control, creating squares of 20 miles on a side, each with a fort from which patrols operated. To connect the forts, they built 850 miles of roads. These protracted conflicts tried the Army’s patience and resilience, and even victory required persuasion and force to keep the peace.

The regulars conducted their Indian campaigns mostly out of sight of the nation’s martial but unmilitary society. Americans disdained professional soldiers as cogs in a machine, but they idealized the self-reliant, undisciplined riflemen led by inspired amateurs such as Andrew Jackson. Military schools that produced white collar professionals flourished, especially in the South, and volunteer clubs drilling in military paraphernalia attracted youths who dreamed of glory, honor and fame. In places, the militia became a major civic organization, serving political and social functions; as a military institution, however, it was in a state of decay. Congress and the states, except in New England, spent little on the militia. In raw numbers of obligated manpower, it was too large to arm and train and existed as little more than an ideal. Mandatory muster days decreased as direct threats to communities declined and pressures increased to keep workers on the job. Stories abounded of musters devolving into farcical drill and drinking sprees. Facing violence and domestic disorder, the militia all too often amounted to little better than vigilantes. When militia joined regulars for service against the Indians, they earned a reputation for poor discipline and violence. Even volunteer units in federal service could be vicious, targeting Indian villages and families, and their often-brutal treatment of civilians during the Mexican-American War confirmed their image among regular officers as a rabble.

In many ways, the Mexican-American War of 1846–1848 was a traditional limited conflict for limited goals. President James K. Polk wanted to seize Mexico’s northern territories and then, by capture of Mexico City, force the Mexican government to sue for peace on those terms. After the War of 1812, many foreign observers expected the Mexicans to give the brash Yankees their comeuppance. But West Pointers showed their professional skill, and American enlisted men proved tough and resilient, marching vast distances and defeating usually superior numbers. Volunteers did well enough to validate advocates of the citizen soldier. Both schools of leadership felt justified. Brevet Major General Zachary Taylor won at Buena Vista by calm resolve and faith in the courage and training of his troops, while the flamboyant Brevet Lieutenant General Winfield Scott devised one of the greatest campaigns in American military history. Landing at Veracruz and driving inland without a line of supply, Scott skillfully deployed the combined arms divisions of his 10,000-man army to outflank and overrun successive Mexican positions and capture Mexico City in September 1847. To avert a large-scale insurgency, he then reached an informal, almost contractual pact with the Mexican people, protecting them from undue hardship, paying for supplies and keeping discipline, but taking harsh measures against guerrillas. Scott’s feat was all the more striking, since many volunteers indulged in racial violence against Mexican civilians. For a time, a protracted war seemed likely, but, despite Polk’s distrust of Scott and efforts to micromanage the situation, Polk’s envoy was able to capitalize on Mexican disunity and war weariness to reach an agreement.

The Civil War

Thirteen years later, the Civil War was a different conflict for the highest stakes: the survival and identity of the nation. Passionate national feeling, religious fervor and racial tensions exploded in a war that, while not total, showed an intensity and level of popular mobilization unseen in America to that point. To Northerners, the conflict was a test of the ability of the great American experiment—God’s chosen nation, with its ideals of liberty, democracy and opportunity—to hold together and achieve its destiny. With the Emancipation Proclamation in 1863, the theme of freedom gave the struggle a new dimension. Northern males felt a duty to preserve the birthright of their forefathers and to demonstrate their own courage and manliness as natural American fighting men. As the war continued and losses rose, enthusiasm waned, and the Union cause turned to bounties, substitutes and a federal draft to fill the ranks. But the sense of an existential struggle continued to motivate Union troops. For all of the Lost Cause mythology of their behavior, they never fully engaged in the unrestrained violence and brutality of total war.

This contest to consolidate and cleanse the American nation-state took place on a scale unimaginable to prewar Americans. Numbering only 16,000 at the start, the regulars—many of whom resigned to serve the Confederacy—were clearly insufficient for the task of subduing an area of 750,000 square miles, roughly the size of western Europe. Initially, President Abraham Lincoln called up 75,000 militia for 90 days, but as the magnitude of the task became more apparent, he appealed for volunteers for three years. In March 1863, Congress passed nationwide federal conscription, but most soldiers continued to be volunteers. In the end, over two million men served in Mr. Lincoln’s Army. The size of the armies and the scale of battles, campaigns and casualties reflected the impact of the Industrial Revolution, with the introduction of railroads and telegraph, and the mass production of uniforms, weapons, munitions and food. It took time to marshal this potential; officials, generals and staffs started with little expertise in the mechanics of mobilization. But with its industrialization, the North had the edge, possessing volunteer experts with the management and technical skills to meet logistical challenges. They used railroads, riverboats and wagon trains to keep up the flow of manpower, arms, equipment and supplies over a continental land mass.

At first, Northern objectives hardly went beyond preserving the Union and restoring the antebellum status quo. The aging Winfield Scott drew up the Anaconda Plan for a blockade and closure of the Mississippi River to strangle the rebellion. But an impatient public that idealized the natural American fighting man saw little need for the organization and training of the raw recruits and the slow development of Scott’s design. Lincoln overrated the strength of Southern Unionism and bowed to the pressure for a quick decision. Only after the debacle at the First Battle of Bull Run did the North accept the more thorough preparation and the more methodical plans of Scott’s successor, Major General George B. McClellan. As General in Chief, McClellan implemented Scott’s strategy with particular success in the West, where Union forces effectively used joint operations to take the entire length of the Mississippi—except from Vicksburg to Port Hudson—and to drive up the Tennessee and Cumberland Rivers to occupy the border state of Kentucky as well as most of Tennessee. Victory at Pea Ridge, Arkansas, confirmed retention in the Union of another border state—Missouri—although the bloody battle at Shiloh indicated the depth of Southern resistance and the long war ahead. When McClellan tried to execute his river strategy in Virginia to capture the Confederate capital of Richmond, he encountered General Robert E. Lee, who defeated McClellan at the Seven Days, took the war into northern Virginia and Maryland, routed another Union army at the Second Battle of Bull Run, threatened Washington and raised the specter of British intervention. The battle of Antietam repelled Lee’s invasion and led to Lincoln’s Emancipation Proclamation.

Lincoln’s proclamation of freedom for enslaved Blacks within Confederate-held areas turned the war into a revolution. Union generals no longer returned escaped enslaved people to their masters; indeed, 180,000 African Americans enlisted in the Union Army and contributed to the eventual victory. Further, Lincoln’s removal of McClellan from command of the Army of the Potomac after Antietam signaled the move toward a harder war, one based less on geometric-like maneuver to capture key points and more on the destruction of Confederate forces and resources. From the start, Southern leaders had embraced guerrilla warfare, forming partisan units to attack Union communications. Unauthorized bushwhackers preyed on Northern troops and Southern civilians alike, committing atrocities and fueling chaos. Union officers reacted by holding communities responsible for guerrilla actions, punishing the actively disloyal through confiscation, burnings, relocation, imprisonment or even execution. Meanwhile, the war reached a turning point. Success at Fredericksburg and Chancellorsville led Lee to try another drive north, which came to a dramatic end at Gettysburg in July 1863. Simultaneously, Major General Ulysses S. Grant took Vicksburg, which, along with Port Hudson’s fall, split the South along the Mississippi. Confederate success at Chickamauga in the fall was followed by Grant’s decisive victory at Chattanooga, opening the way to the Southern heartland.

Under a new Union general in chief, Grant, and his top subordinate, Major General William T. Sherman, the war’s last year featured a grinding campaign of attrition against Confederate armies and resources. Against Lee’s skillful tactics, Grant, in personal command of the Army of the Potomac, could not annihilate the Army of Northern Virginia, but he wore it down with constant, aggressive maneuvers and attacks, even though his own army suffered such terrible losses that some units refused further frontal assaults. By July 1864, Grant had pinned Lee in trenches at Petersburg. In Georgia, Sherman maneuvered his way to the key industrial and communications center of Atlanta, beat back costly Southern assaults and occupied the city in September. After burning Atlanta, he marched his army across Georgia to Savannah, destroying railroads and crops, and driving home the cost of war to Southerners. In the Shenandoah Valley and at Nashville, Major General Philip H. Sheridan and Major General George H. Thomas annihilated armies facing them, and cavalry raids extended the devastation throughout the Valley and the Deep South. As violence spread in occupied areas, Union forces burned houses and used outposts, patrols, sweeps and special units to hunt down guerrillas, with, at best, mixed results. Desertion became a major problem for Southern forces as discouraged, hungry troops returned home to support their destitute families. Finally, in April 1865, Grant forced Lee’s surrender at Appomattox Court House, while Sherman, who had driven up through the Carolinas, accepted the capitulation of the Confederate army there. By June, the remaining Southern forces had laid down their arms.

The U.S. Army had won the war, but now it had to win the peace. Over a million veterans returned home; by January 1866, only 88,000 Union troops remained to occupy the South. The Army was supposed to maintain order and uphold the rights of all citizens. It was also supposed to help the War Department’s Bureau of Refugees, Freedmen and Abandoned Lands to protect the formerly enslaved and to assist the poor of both races to find jobs and education while distributing rations, clothes and medical care. When President Andrew Johnson gave little support to freedmen rights, the Army looked to Congress for aid in its mission. Congressional Reconstruction in 1867 put the South under the rule of five military district commanders with sweeping powers to protect persons and property and to transfer court cases to military tribunals. But by then, the Army only had 20,000 troops to police the entire South, and state guard units and Black militia offered only limited aid against the intransigence of the White South toward the new political and social order. Sporadic harassment developed into irregular warfare as White terrorists, including the Ku Klux Klan, killed, robbed, raped and otherwise intimidated White Unionists and Blacks across the South. The Army was caught in the middle. By then, most officers were more concerned with stable government than radical change and were skeptical of altering Southern views by force. And the political climate was shifting. In the 1870s, idealism waned in the North in the midst of economic depression. Most Northerners were more interested in reconciling White Southerners and foregoing social reforms. In 1877, President Rutherford B. Hayes withdrew the last federal troops from the South.

The Last Years of the Frontier Constabulary

Most of the Regular Army had already returned to its duties on the frontier. Although neighboring communities in the West thrived with posts as customers—and railroads and the telegraph connected the frontier with the East—in general, the frontier Army felt separated from civilian society. Officers disdained the profiteering capitalists on the East Coast, yet often lived like lords with their wives, hunting and holding picnics, balls and amateur plays. As before the war, enlisted men, largely unskilled immigrants, lived an austere life of low pay, bad food, severe discipline, little training and manual labor to construct and maintain forts and roads. The segregated postwar Army included two infantry and two cavalry regiments of African Americans, who shared campaigning and the rugged conditions of the West. While a color line certainly existed, and racist officers and communities blighted the lives of these soldiers, the Army did not have the resources on the frontier to discriminate in terms of mounts, equipment, uniforms or duties. Black and White troops both contributed to continental expansion, providing supplies and security for the construction of the transcontinental railroad, completing surveys of the Western lands, exploring the newly purchased territory of Alaska and the northwest coast of Greenland, and even supervising the new national parks, where they regulated access, set boundaries, developed trails and roads, and fought forest fires.

As ever, the main focus of the frontier Army remained the Indian. Often at odds with the Bureau of Indian Affairs, with whom it shared responsibility, the Army negotiated relocation treaties, kept order and worked to assimilate natives into White culture. But many Indians had no intention of moving to reservations; when they resisted, the Army had to coerce them. Once again, soldiers needed to pin down an elusive enemy. Plains and Southwest Indians were hardy nomadic or seminomadic nations, for whom war—in the form of raids and ambushes—provided wealth and status. The Army sought mobility from cavalry and pack mule trains, and it required intelligence, which it obtained through the use of Indian scouts. Once again, its frustration with Indian tactics led to attacks on the natives’ homes and food, without which they could not survive in the harsh climate. Although Army policies precluded wanton slaughter, they allowed destruction of property and food supplies and the execution of especially incorrigible individuals when compelled by military necessity. A lot of carrot and stick was necessary, as junior officers balanced military action with appeasing local populations. While many of them had empathy for the Indians in their struggle to survive, their cultural backgrounds still led them to see natives as inferior, uncivilized and essentially doomed. Occasionally, the Army’s faith in its leadership, tactics and discipline was misplaced, as the Fetterman Massacre in 1866 and Little Bighorn in 1876 showed. But relentless campaigning combined with the pressure of advancing White settlement ended Indian resistance across the West by 1890, when the Census Bureau announced the frontier’s closing.

Elsewhere, the Army reverted to pre-Civil War duties in an era of few external threats. In 1866, Sheridan led 52,000 troops to Texas to induce the French to withdraw support from their puppet regime in Mexico. Postwar friction lingered with Great Britain over the damage that Confederate raiders, built in English shipyards, had done to the North’s merchant marine. But a treaty in 1871 settled those claims. The Army went back to enhancing coastal fortifications, as the Endicott Board’s report of 1886 eventually led to replacing the masonry forts demolished by Civil War rifled artillery with a new system of low-lying works, a few powerful and retractable guns and fire control. Engineers built levees and improved navigation facilities, while the Signal Corps laid thousands of miles of underwater cables and telegraph lines. As anxieties arose over labor wars and riots, federal marshals often called on regulars to break strikes and enforce local laws. During the Great Railroad Strike of 1877, President Hayes sent federal troops to protect government property and to maintain order at the request of governors or federal judges. After the Posse Comitatus Act of 1878 forbade the use of federal troops against domestic disorders without authorization by the Constitution or Congress, governors turned to the organized militia—the National Guard. Similar to the volunteer organizations of antebellum America, the Guard was, in part, a social association that young men joined to show their “Americanness” and citizenship. But in reality, between the Civil War and 1906, state governors called Guard units on as many as 481 occasions, mostly reacting to civil disorders. Unfortunately, this earned the Guard disdain by some in labor as strikebreakers and tools of the elites. By most appearances, the Army had changed little as the new century approached.

The Expeditionary Army; 1890–1917

But change was coming. Professional officers knew in the 1870s and 1880s that the days of Indian fighting were numbered. Sherman, the Army’s commanding general, realized the Army needed a new focus, even if he also admitted in 1880 that the idea of a hostile force landing on the American coast was simply preposterous. Memories of the Civil War were fresh, and regular officers were still more inclined toward conventional European standards. Thus, the key military challenge became the preparation of great armies of citizen soldiers to meet the demands of modern warfare, and the model of the Germans, who had just roundly defeated the French in 1871, was gaining ascendancy. Reacting against unpreparedness during the Civil War, Colonel Emory Upton drew on the old idea of an expansible Army, which would add mobilized citizen soldiers to a professional cadre that would organize and train them. He also called for a general staff to replace the War Department bureau system that had created so many conflicts between the Secretary of War and staff on the one hand, and the Commanding General and line on the other. The Army did not adopt these ideas, but it did establish branch schools that provided some rudimentary technical education. A new Military Service Institute published a journal that, along with a lyceum program, provided a forum for the discussion of military issues.

The trend toward greater professionalism reflected several changes in a society that, in the 1890s, combined enormous turmoil with a growing sense of insecurity. In a world shrinking under the impact of new technology, the threats of invasion from overseas—especially from a rising Germany—were more plausible in the public mind. Although the nation had become an industrial behemoth, it was riven by economic depression, labor troubles, rising racism and immigration from ethnicities that seemed less assimilable into the old White, Anglo-Saxon population. Popular Social Darwinism perceived a struggle among nations and races for survival, and social critics wondered, with urbanization and the frontier’s closing, if the nation had become too soft, materialistic and domesticated. Some, like Theodore Roosevelt, lionized the vibrant man of action who used the intense experience of war to build the virtues of courage, toughness and self-discipline. Enough faith remained in Protestant ethics and the American system for people to believe in divinely ordained progress, rational social engineering by professional experts and the superiority of Anglo-Saxon civilization. If technology made war more destructive, maybe it also made it more decisive and shorter—and therefore served a benign purpose.

It was in this turbulent environment that the nation shifted from continental to overseas expansion, a new version of Manifest Destiny and America’s role in the world. Much of the impetus came from enthusiasts like Roosevelt, who felt that colonies were an appropriate expression of rising national power and fulfilled the duty of White nations to educate the peoples of Asia and Latin America. In a time of economic turmoil and intense global competition over trade, access to new markets and strategic control of shipping lanes from coaling bases appealed to many Americans. Racism figured on both sides of the debate, as advocates of the “White Man’s Burden” confronted anti-imperialists who pointed to the problems of assimilating foreign peoples. Expansionists distinguished American from European colonialism by stressing the American sense of mission and humanitarian motives. The decision for empire, however, came haltingly and in stages during and after the Spanish-American War of 1898.

Although the Army performed better in the war with Spain than its prewar status would have led one to expect, its amateurish performance showed its inexperience with expeditionary warfare. The basic objectives were to induce the Spanish to give up their attempts to suppress the Cuban Revolution and to enhance Caribbean stability and the Monroe Doctrine. But the Army again struggled to organize, equip, train and care for raw volunteers, including National Guardsmen who would volunteer for service overseas. After the specter of Spanish naval squadrons raiding Atlantic cities aroused public hysteria, the rushed departure for Cuba of Major General William R. Shafter’s V Corps—with its mix of regulars and eager volunteers seeking their rite of passage through combat—fell into utter chaos. In Cuba, the Army conducted a campaign to seize capitals and major cities, positional objectives whose fall would presumably provide leverage at the peace negotiations. But in the July drive on the port of Santiago, where the Spanish fleet had taken refuge, the V Corps showed physical courage but tactical incompetence, reflecting the inexperience of its officers with operations on such a scale. Scouting, communications and security all proved inadequate, and piecemeal attacks without proper coordination produced useless slaughter at San Juan Hill, despite the bravery of the troops, including dismounted African American cavalrymen and Roosevelt’s Rough Riders. On 16 July, Santiago surrendered after a futile escape attempt by the Spanish fleet. Other expeditionary forces landed in Puerto Rico and in the Philippines to secure Commodore George Dewey’s naval victory in May at the battle of Manila Bay.

When President William McKinley decided to keep and “civilize” the Philippines, Filipino rebels had already extinguished Spanish rule in much of the archipelago and were soon in conflict with the Americans. In February 1899, Emilio Aguinaldo’s 40,000 men exchanged fire at Manila with Major General Elwell S. Otis’s 20,000 troops. Otis drove them from Manila, inflicting severe defeats on the poorly trained and ill-equipped Filipinos. With Aguinaldo having fled to the northern Luzon mountains, rebels led by local elites turned to guerrilla tactics, hiding among the native population and conducting raids and ambushes. Otis responded with outposts to protect the population and to provide bases for small patrols to find and destroy the guerrillas and their camps. As in Mexico and the South, the Army adopted a carrot-and-stick strategy, encouraging good behavior while striking hard at those enemy formations it could find, keeping up the pressure until the bandits grew weary of living in the mountains and the people tired of supporting them. It took advantage as well of class, religious and ethnic divisions within Filipino society; 15,000 Filipinos eventually took up arms against the revolutionaries. Much lay with the junior American officer in the field; he had to decide what pacification policies to adopt in his area and to be patient, empathetic and firm, using force and persuasion as needed. As the war lingered through 1900 and 1901, colonial officials used more refined tactics, such as psychological warfare and surveillance, while granting more self-government.

Gradually, the Army wore down the insurgents. In March 1901, a raid captured Aguinaldo. An ambush of American troops in Samar in 1901 led to harsh measures, such as burning crops and villages, torture and relocating the population. More typical was Brigadier General J. Franklin Bell’s pacification of Batangas, employing timely intelligence, population resettlement and mobile cavalry patrols with native scouts to keep constant pressure on the guerrillas. The last major insurrection leaders surrendered in July 1902.

But the Philippine War was just the start of such missions. Over the next decade and a half, American troops found themselves in a series of small wars from the Caribbean to East Asia. In 1900, when Chinese insurgents called Boxers encircled Western embassies in Beijing, 2,500 American soldiers and Marines joined an international rescue effort. From 1906 to 1909, 6,000 soldiers and Marines returned to Cuba to restore order after clashes over a rigged election. From 1902 to 1913, operations in the Philippines continued, especially in the southern half of the islands, where independent warrior clans and bandits resisted U.S. authority. In Mindanao, when Muslim datus rejected American overtures, the Army again used the carrot and the stick, conducting punitive patrols and wiping out fortified villages, but also constructing roads, schools and hospitals. Army troops and Marines occupied the port of Veracruz in April 1914 after an international incident involving American sailors in Tampico. When Pancho Villa’s Mexican revolutionaries raided Columbus, New Mexico, in March 1916, President Woodrow Wilson sent Brigadier General John J. Pershing’s Punitive Expedition to capture or kill Villa and disperse his band. In an operation that, in some ways, hearkened back to the Indian Wars, Pershing’s horse cavalry chased Villa over 1,600 rugged square miles of northern Mexico. But Pershing encountered opposition from the Mexican government and people, and, when war threatened, Wilson called 75,000 National Guardsmen into federal service. For the first time, the National Guard emerged as the Army’s primary reserve for mobilization. In the end, the nation averted a major conflict, and Wilson withdrew the Punitive Expedition. 

With the beginnings of an American empire, the Army received new responsibilities. Soldiers became governors, involving a different set of skills. In ruling over colonial peoples, they drew on their background with the Indian Wars. Both Pershing and Major General Hugh L. Scott had commanded Black units and native scouts, and Scott in particular developed a fascination with Indian languages and culture. They kept their paternalistic beliefs in the innate superiority of White civilization over more primitive peoples but also showed common sense, subtlety and an ability to work with local elites in Cuba, the Philippines and Mexico. In Cuba, the Army flooded potential trouble spots with troops while carrying out public works programs and legal reforms and while training a Cuban army and rural guard. A medical commission under Major Walter Reed traced yellow fever to mosquitoes, and the Army moved to eliminate the insect’s breeding grounds in Cuba and American territories. The conquest of yellow fever enabled the construction from 1907 to 1914 of the Panama Canal, a massive engineering feat that opened a pathway between the oceans. The first years of the century also saw more involvement by the Army in humanitarian relief after natural disasters. In 1906, soldiers fought fires and provided supplies to victims of the San Francisco earthquake. They also aided flood and tornado victims and fought forest fires across the nation.

For the Army, it was a turbulent time. Its missions now included the defense of territories that lay at some distance from the mainland but within range of potential enemies, especially the rising power of Japan. The volatile international situation led one senior general to remark that it would be easier to conduct an operation from Europe against New York than it had been for Grant to conduct his campaign against Lee. The Army was adjusting to numerous technological innovations, from breechloading rifles and artillery to trucks and airplanes, which made their operational debut in Mexico. Officers focused their studies on major conflicts in the belief that an Army trained for modern war could defeat any semi-civilized foe, but troops adept at small unit tactics would find the transition to large unit operations difficult. At Fort Leavenworth, Kansas, staff college classes used the model of the Franco-Prussian War and the writings of Colonel Arthur L. Wagner to argue that modern war begins and ends quickly and involves large armies making full use of industrial technologies such as the railroad and telegraph to destroy enemy armies. As posts became more accessible and comfortable, a more cosmopolitan officer corps interacted with the larger society and with colleagues via professional journals and schools. It shared the concerns of elites about the impact of urbanization and immigration on the American moral fiber, even as immigrants transformed the Army into a melting pot. The Progressive Era’s managerial revolution, with its centralized bureaucracies and managers, also affected the Army. A new type of professional officer emerged: an educated, rational supervisor of violence rather than a romantic warrior.

Under the leadership of Secretary of War Elihu Root, the Army instituted several reforms to create a modern Army for major conventional conflicts. It formed a new Army War College, a General Staff and Service College at Leavenworth, five service schools, and garrison programs to teach tactics and administration to lieutenants and captains. In place of the old bureau system and commanding general, it created a chief of staff and a general staff that would carry out long-range strategic planning, although the bureau chiefs would remain powerful for many years to come. The Dick Act of 1903 reorganized the militia into the Organized Militia, or National Guard, and the Reserve Militia, and it stated that the Guard would pattern its organization and equipment after the Regular Army. Essentially, the act provided federal dollars and equipment in exchange for Army standards and control of training; additional legislation in 1908 gave the president full power to call out the Guard during national emergencies and removed limitations on service time. Formation of the Medical Reserve Corps in 1908 was a first step toward a federal reserve that included graduates of the Reserve Officers’ Training Corps (ROTC) programs at land grant colleges. A new Army Nurse Corps enhanced the role of women in the Army. Yet, the service still had far to go to become a truly modern ground force, as it remained scattered in posts across the United States and overseas, its corps and division structure purely theoretical, proficient in small unit tactics and marksmanship, but unprepared for operations by anything larger than a regiment.

The Mass Citizen Soldier Army of the Industrial Age; 1917–1945

World War I and the Inter-War Years

When the United States entered World War I in April 1917, most Americans saw the conflict as a righteous crusade against a brutal, militaristic autocracy in Germany. Economic interests and cultural affinities influenced American sentiments in favor of Britain and France, but the country went to war with an air of patriotic moral certainty hard to fathom in later, more skeptical years. In God’s cause, the nation would eradicate evil and reform the decadent world order according to Christian democratic ideals and American principles, which Americans saw as universally applicable to every society. The prevalent euphoria disguised deep concerns regarding the divisions in American society. Particularly in the Midwest and West, isolationists grumbled that the cataclysm was a rich man’s war and no concern of the United States, while nativists worried over the loyalties of large, ethnic minorities like the German-Americans and immigrants from Austria-Hungary. President Wilson’s goals, while idealistic, were also more practical: to have major influence at the postwar peace conference that would create the new global order. Given that the catalytic cause for intervention was German unrestricted submarine warfare, the nation could have fought a purely naval war against the U-boats, but Wilson believed that the presence of an American army on the Western Front—where huge armies, massive artillery fire, machine guns, poison gas and barbed wire ruled—would give him more leverage. He also made sure that the Army would fight as an independent force, not as mere replacements for Allied armies.

The scale of American mobilization was unprecedented, but the results for the world’s biggest economy were disappointing. Even before the declaration of war, the general staff had decided conscription would be necessary to create a mass army for Europe. In April 1917, the Army only contained 130,000 men, plus 80,000 National Guardsmen still in federal service. Fortunately, Americans accepted a more activist federal government, and the draft, operating through boards of local citizens, enabled the Army to send two million men to France by war’s end. The draft drew on the diversity of American society, as the Army, in handling ethnic minorities and immigrants, blended Americanization with a respect for cultural differences, even providing multilingual officers in some cases. Women served as clerks and nurses, and over 200 “Hello Girls” worked switchboards for the Army in France. African Americans enlisted to justify more citizenship rights in the Jim Crow era. Responding to public concern about conscription and fear that military life would expose young soldiers to drinking, gambling and prostitution, the War Department initiated a massive program of sports, movies, libraries and music to entice the ranks with more wholesome entertainment. But Army efforts to mobilize American industry fell short. Prewar planning for mobilization was almost nonexistent, and during the first months, 11 uncoordinated War Department bureaus competed for scarce resources. Only after a near collapse of mobilization in late 1917 did the Army finally turn to a more centralized, formal structure that could set priorities. By that time, it was too late. The Army had to rely on the Allies for most of its tanks, artillery and planes.

It took time for Pershing’s American Expeditionary Forces (AEF) to join the fray, and, when it did, the Army’s inexperience with large unit operations showed. American officers were aware of the principal concepts of industrial age warfare, using fire to enable movement and concentrating all available firepower at the decisive point before the final assault. But the AEF needed more materiel preparation and tighter coordination between infantry and artillery. Its doctrine of open warfare stressed the ability of infantry to move fast and fire frequently and accurately, but it underestimated machine guns and artillery—an approach suited to Luzon and Mexico, but not to the Western Front. The green doughboys lacked training, and division commanders failed to coordinate artillery, resulting in horrendous losses. Too many junior and noncommissioned officers lacked basic tactical and leadership skills, and they used outdated practices or methods that were poorly adapted from European experiences. The few Leavenworth graduates played a key role on higher-level staffs, but too many clashes occurred between senior commanders and staff officers who inappropriately exercised authority. In the AEF’s big test in the Battle of the Meuse-Argonne, it bogged down in the rugged terrain as commanders struggled to coordinate the advance of their 28,000-man divisions. Over 47 days of combat, 26,000 American soldiers died. But the doughboys fought with courage—as shown by the feats of such heroes as Corporal Alvin C. York, Lieutenant Samuel Woodfill and the Lost Battalion. They persevered, learned much in a short time and aided the final victorious Allied drive.

Armistice Day, 11 November 1918, came before the full weight of American arms joined the battle. Within a month, the Army released 650,000 troops, and, within nine months, it had demobilized over three million. A contingent of Americans joined British and French forces in the occupation of the Rhineland before departing in 1923. In August 1918, President Wilson sent 15,000 doughboys into revolution-torn Russia on a complex mission to secure supplies the Allies had sent to the tsarist regime, assist the Czech Legion in its withdrawal from the Eastern Front, watch Japanese designs on Siberia and appease the other Allies, who sought to overthrow the Bolsheviks. The intervention ended in fiasco as, with the main war over, American troops found they were in an untenable position, lacking resources, support or a clear purpose. The force in Northern Russia finally left in June 1919, and the Siberian contingent followed in April 1920.

As the Army looked back on its World War I experience, an obvious lesson was the need to improve mobilization, both of men and of industry. Colonel John M. Palmer, a key postwar planner, believed that the most important military problem facing the United States was devising the most effective means for preparing armies of citizen soldiers to meet the demands of modern war. In 1920, he was instrumental in the formulation of an amendment to the National Defense Act, authorizing a peacetime structure of a 300,000-man Regular Army, a National Guard of over 430,000 men as the main federal reserve force, and an Organized Reserve with a pool of officers who, in wartime, would provide cadres for skeleton divisions that draftees would fill. The act called for nine corps areas, each with a regular division, two National Guard divisions and three reserve divisions as a nucleus for expansion. Under the auspices of a new Assistant Secretary of War, military planners would draw on the expertise of various industries to develop a series of Industrial Mobilization Plans, a key step that illustrated the closer relations between the Army and businessmen. During the 1930s, the Army created four Industrial Mobilization Plans that laid out the stages of mobilization up to entry into war. The Army instituted the Army Industrial College to prepare officers for mobilization planning. To train officers for the anticipated citizen army, it expanded its support for ROTC programs at colleges and universities and for Citizens Military Training Camps (CMTC), where, for 30 days each summer over four years, young men could train and get a Reserve commission.

The high casualty rates of World War I drove the Army to improve its conduct of combined arms by large units. Even while insisting that human intangibles like will and courage remained the dominant factor in war, Army leaders noted the domination of the World War by machines and technology. Still, Pershing, a former cavalryman and now chief of staff, saw trench warfare as an anomaly and believed the service would most likely campaign on the North American continent, where mobility was especially critical. Thus, doctrine stressed maneuver, open flanks screened by horse cavalry, and turning movements and envelopments converging on key points. With skeleton units and an overlarge officer corps, officers devoted much time to education, since the prospect of wartime expansion meant that staff-trained personnel would be at a premium. Army schools sought to develop logical, balanced staff thinking over brilliant generalship and focused on principles of war and the infantry-artillery combined-arms team with the introduction of tanks and aviation to overcome defensive firepower. Along with the old Jominian stress on lines of operation, students studied Clausewitz’s emphasis on the center of gravity, which generally meant the main enemy army, as the key objective. As for small wars doctrine, the Army left most of the work to the Marines, but it published materials that emphasized adaptation, intelligence and awareness of ethnocentricity. Aviation was supposed to have a vital role for reconnaissance and close air support of ground troops, but aviators were increasingly fascinated by the notion of strategic bombing that could hit vital rear areas and collapse the enemy’s will to resist.

Any impulse toward innovation, however, faced tight budgets and a lack of urgency on defense issues. Although still involved in international politics, the nation focused more on domestic affairs. An aviation craze was just one expression of a growing, multiethnic society enthralled by machines, mass production and systems. Yet, change unsettled a people nervous about old Victorian certainties and values and the possible loss of an older, more virtuous, vital republic. Then came the Depression’s bleak landscape of fear, pessimism and despair that led many to doubt American institutions and only deepened isolationism and antimilitarism. The only plausible threats of the interwar era seemed to be a Pacific war with Japan—which receded for a time in the 1920s—or further Mexican border troubles. The Army cooperated with the Navy on Plan Orange to defend Hawaii and the indefensible Philippines. Overall, complacency was fed by faith in the citizen soldier and an American industrial capacity that made any peacetime buildup unnecessary. Congress provided no funding to build the Army anywhere near the levels envisioned in the National Defense Act, and it shrank to under 138,000 troops, scattered across the United States and overseas. Lack of money affected just about every Army activity. World War I left the service with increasingly obsolete equipment that Congress would not replace while it was usable. Large-scale maneuvers were impossible with such a dispersed force. Soldiers received low pay, lived in rotting barracks, and used war surplus food and clothing. The Army tested tanks, trucks, planes, artillery and better communication devices, but it lacked the funds to procure them in any quantity.

Lack of funding was not the only reason for slow innovation. The Army of the 1920s was a tight-knit, conservative institution, clinging to traditional values while also reflecting social views of the larger society. Many officers feared the nation’s racial stock was being undermined by immigration and intermixing with inferior races and ethnic groups. They felt a closer kinship with corporate America, with whom they had worked on mobilization during the war and whose expertise in managing large organizations they respected. Due to the hump of new officers who entered the Army in World War I, promotions slowed. Bureaucratic politics and prevailing paradigms hindered change, nowhere more so than in the development of tanks. During the 1930s, the chief of staff, General Douglas MacArthur, reimposed divided responsibility for armor between the infantry and cavalry branches, neither of which did much to advance tanks beyond a slow infantry support citadel or a fast armored car. The cavalry branch was ruled by traditionalists who, while allowing experimentation with mechanization, still believed in horse cavalry, even using trailers to carry horses to their operating destination. Army intelligence capabilities had a low priority, except for some attaches. Doctrine in 1939 failed to reflect the technical and organizational changes that many other armies were adopting on the eve of World War II. The Army continued flood control programs and preservation of domestic order, ejecting the Bonus Marchers from Washington in 1932, and in 1933, it assisted President Franklin D. Roosevelt’s New Deal with the supervision of the Civilian Conservation Corps, which put young men to work on reforestation and public works.

Fortunately for the Army, it would have some time to prepare for American entry into World War II. When Adolf Hitler invaded Poland in September 1939, the Regular Army ranked 17th among world armies, with just 190,000 men; the National Guard had 200,000 and the Reserve 110,000. At first, the Army did little more than fill out its authorized strength, conduct some large unit maneuvers and help develop the so-called Rainbow plans for war on multiple fronts against a coalition of enemies. The fall of France in June 1940, however, shocked American leaders, the military and the public, all of whom now had to face the implications for national security of a single power dominating the European continent. Defense spending rose sharply, Roosevelt called up 18 National Guard divisions for a year’s service, and, in August 1940, Congress approved the nation’s first peacetime draft. The Army dusted off its plans for industrial mobilization and worked to expand capacity for military production. Roosevelt created an Office of Production Management under William S. Knudsen, a General Motors executive turned Army lieutenant general, to work with businesses on military contracts, and he established a Supply Priorities and Allocation Board under business executive Donald M. Nelson to coordinate resources between consumer and defense needs. Meanwhile, the Army formed officer candidate schools to train the hordes of new officers required by mobilization, housed and trained the draftees, conducted large-scale maneuvers in Louisiana and the Carolinas, and rewrote manuals for mechanized warfare, adding tanks, trucks and aviation to the traditional infantry and artillery team.

World War II

When Japan attacked Pearl Harbor in December 1941, the United States and its Army entered the “Good War,” which seemed the logical outcome of their evolution as a virtuous, destined people. In its narrative of good versus evil, its mobilization of industry and technology, its large-scale conventional operations, even its start with a supposedly unprovoked, Indian-style surprise attack, the conflict fit American ideas of warfare. Once more, the country was engaged in a crusade, although it was less a mission to reform the world than a necessary reaction to a real threat, requiring grim, practical resolve by a unified nation to win total victory over totalitarianism. The Army worked with a patriotic but independent mass media that assumed new importance in mobilizing public opinion. While America’s pluralist society had permitted various ethnic groups to live and work together, it still retained racial tensions, class divisions and set gender roles; within months of Pearl Harbor, Japanese Americans were headed to relocation camps. After their World War I experience, African Americans were skeptical that this endeavor would ease segregation and discrimination, and indeed, only a relative few served in combat units. The new Women’s Army Corps assigned personnel almost entirely to clerical and service jobs while stressing their personnel’s proper, feminine appearance. Through common service, White males from various ethnic groups learned to work together even as the nature of the war left individuals feeling like anonymous, interchangeable parts of a larger machine. The Army’s success in pulling together these volunteer and draftee citizen soldiers with its professional, often empathetic leaders raised it to new levels of prestige and popularity.

For the most part, American generals showed solid competence, if not brilliance. At the strategic level, General George C. Marshall, the chief of staff who built the World War II Army, played a central role in Allied leadership councils, and Army staff officers contributed much to combined and joint planning and to conducting the war as part of a coalition. Historians have often referred to the American strategy of annihilation, and indeed, commanders sought the destruction of enemy forces and penetration into the enemy’s heartland to force its unconditional surrender. Still, much of the war consisted less of the mobile operations of legend than grinding battles of attrition through rugged terrain and severe climate against prepared enemy fortifications. In Europe, with few open flanks available, the Army created penetrations with the overwhelming firepower of combined arms against a specific sector, with secondary attacks to divert or pin down enemy forces. Then it exploited with the mobility for which it became famous. But it was still an infantryman’s Army with its focus on flanks and terrain, careful planning and precise balancing of forces in the attack, and emphasis on the combined arms team to clear the way. The service showed its aptitude in firepower, mobility and the materiel abundance that American economic power made possible. At the level of maneuvering armies or groups of armies, however, the Army was still in the learning stage.

Even after peacetime mobilization, it would still take another year before the Army could intervene in any strength in any theater. The Japanese quickly seized Wake Island and Guam in the Pacific and drove into Southeast Asia and the Philippines, where American troops surrendered after a four-month battle against heavy odds. From prewar overconfidence, American troops came to fear the Japanese, who seemed invincible in the thick jungle terrain. Only at Midway in June 1942 did the U.S. Pacific Fleet decisively stop the Japanese advance. Nor were the Allies doing much better elsewhere. The Germans renewed their offensive into Russia, driving for the Caucasus oilfields, and for a time, Soviet survival seemed doubtful. In North Africa, Field Marshal Erwin Rommel’s Afrika Korps advanced into Egypt, threatening the Suez Canal. And German U-boats were carrying out their attacks on Allied shipping to the Atlantic and Gulf coasts, sinking tankers and freighters in full view of vacationers on beaches. Even if the Allies had taken control of the Atlantic shipping lanes, few American divisions were ready to cross the ocean and carry out the Allies’ Germany First strategy. Army planners estimated the nation would need over 200 divisions, but the demands of other services, support units and American industry drained much manpower. In the end, the Army was only able to create 90 divisions; even by mid-1942, those they had still lacked equipment, training and competent leadership. American industry was still converting to wartime needs and trying to satisfy the needs of allies as well as the U.S. services. Not until 1943 did American production figures surpass those of the Axis by a great margin.

By 1943, the tide of war was turning in the Allies’ favor. At Stalingrad in February, the Axis suffered its first major defeat on the Eastern Front. Allied convoys and patrols gained ascendancy over the U-boats in the Atlantic, opening the way for a huge buildup in England for the cross-channel invasion. By the summer of 1943, the Eighth U.S. Air Force in England had amassed the strength to bomb key German industries. Early in 1943, in the Pacific, American troops emerged victorious on Guadalcanal, Buna in New Guinea and Attu in the Aleutians. For the rest of 1943, MacArthur’s American and Australian forces leapfrogged up the Solomon Islands chain and along the New Guinea coast; in November, the Americans began their offensive through the archipelagos and atolls of the Central Pacific. In North Africa, after the decisive victory at El Alamein in October 1942, British/Commonwealth forces under General Bernard L. Montgomery drove the Axis across Libya while Lieutenant General Dwight D. Eisenhower’s armies advanced from their landings in Morocco and Algeria in November 1942 to meet Montgomery in Tunisia. In May 1943, the Axis in North Africa surrendered, opening the way for an invasion of Sicily in July and of Italy in September, knocking Italy out of the war. The advance up the Italian boot, however, slowed in the rugged terrain and rains of late fall. As various mobilization boards set priorities and coordinated production, the Arsenal of Democracy turned out tanks, planes, vehicles and hordes of munitions for all of the Allies. From New Guinea to Tunisia, the Army was learning large-scale, combined-arms operations in varying terrain, with air and naval support, working with Allied forces.

The last year of the war showed how far the Army had come. On D-Day, backed by naval gunfire and aerial bombing of transportation routes, the Army gained a foothold in Normandy. To advance through the rugged hedgerow country, GIs improvised tactics and adapted technology before, in late July, the COBRA breakout started the rapid drive across France to the German border. The Army did not enjoy great numerical superiority over the Germans, but it compensated with superbly coordinated artillery, unmatched mobility, an intimidating abundance of materiel and tight air-ground coordination, based on Allied air superiority. American technology was not always superior—German tanks had more firepower and armor—and lack of fuel and artillery ammunition hampered operations at different stages of the campaign, but Army logistics met the challenge to a degree that astonished foreign observers. Yet, by stopping Hitler’s last counteroffensive in December, the GI showed a tenacity and resilience that his plentiful resources often obscured. From that point, Eisenhower’s broad front offensive drove across the heart of Germany to meet the Soviets, who had overrun Eastern Europe and captured Berlin. In the Pacific, the Army, along with the Navy and Marines, conducted multidivisional operations across thousands of miles of ocean. When the Japanese withdrew into caves and tunnels to avoid naval and air bombardment, the GIs, no longer intimidated by enemy jungle superiority, dug them out with bulldozers, flamethrowers and grenades in a vicious struggle. As U.S. forces rained incendiaries on Japanese cities, took the Philippines and Okinawa, and approached Japan, two atomic bombs developed by the Army’s Manhattan Project brought the conflict to an end in August 1945.

Turning Point: A Standing Draftee Army for the Cold War

New Responsibilities and the Atomic Revolution

In August 1945, the United States was clearly the world’s single most powerful country; yet in many ways, it was more insecure than at any other time in its history. The American homeland, with its peerless industrial capacity, had suffered almost no damage during the war, and American casualties, while heavy enough, paled compared to those of other countries. The nation’s enormous armed forces stood victorious in Europe and the Atlantic, Asia and the Pacific, Africa and the Mediterranean. Yet, for a nation used to blissful isolation from world troubles, the situation was unsettling. The second global conflict in 25 years revealed a streak of irrationality and cruelty disturbing to those who, at the start of the century, had envisioned Western civilization progressing ever upward. That civilization could no longer view technology solely as a benign and positive influence; indeed, in the wrong hands, science and technology could destroy it. Technology had also brought the North American continent closer and more vulnerable to potential adversaries, and the collapse of the European empires and balance showed that the nation could no longer depend on geography and foreign powers and rivalries for its security. Indeed, it now had much greater responsibilities for maintaining a world order favorable to its interests. And strategists also had to consider the impact of atomic weapons. Having passed through two incredibly destructive world conflicts, was another war with such weapons thinkable? Could conventional conflicts still resolve political issues in this new age without escalating to unacceptable levels of destruction?

Barely had the United States emerged from one global crusade when it found itself in another confrontation: the Cold War against international communism. At a time of great pride in American might, faith in their ability to solve problems and a sense of national destiny, Americans faced the prospect of a long, existential conflict against a foe—the Soviet Union—with a potent, subversive ideology counter to America’s liberal creed of free enterprise. The very abundance of American society raised doubt whether the country had the toughness and stamina to outlast its adversary. Others feared that, in an era of perpetual warlike tension and paranoia, the nation might transform into a garrison state that sacrificed its liberties to maintain its security, a development that the anti-communist witch hunts of the late 1940s and early 1950s only seemed to confirm. As communism spread across Eastern Europe and threatened Western Europe and the Balkans, the United States adopted a containment policy, drawing a line against further communist expansion. In rapid succession, President Harry S. Truman’s administration instituted the Truman Doctrine to aid countries threatened by communism, the Marshall Plan to rebuild war-torn Europe and—breaking the tradition of nonentanglement—the North Atlantic Treaty Organization (NATO), an alliance to deter a Soviet attack on Western Europe. World War II reinforced the concept of science and technology as the defining factor for victory, and the nation, for the moment, rested secure in its atomic monopoly. That changed in 1949 when the Soviets exploded their first atomic bomb. During that same earthshaking year, Mao Tse-tung’s Communists took over China, and the Truman Administration considered a new defense buildup.

For the Army, the five years after World War II were difficult. Demobilization turned into disintegration as domestic pressure to “bring the boys home” led to such a rapid downsizing that the Army lacked troops to cover its many postwar responsibilities. Frenetic demobilization had an impact on the occupations of Germany and Japan, the service’s primary postwar mission, as bored, unhappy soldiers who were eager to go home created disciplinary problems, despite efforts to introduce leisure activities and post exchanges. The arrival of military families later in the occupation helped mitigate abuses and also provided unofficial ambassadors for the American way of life in their host nations. Lack of personnel precluded the thorough societal transformations that planners had anticipated in the occupied countries and forced considerable reliance on the native populations, including some reactionaries, for their own rejuvenation. Still, the occupations did accomplish a great deal in restoring order, responding to shortages, preventing the reemergence of fascist ideologies and fostering democratic, antimilitarist governments. With the emergence of the Cold War, they increasingly shifted from implementing reform to enlisting their hosts in the struggle against communism. Elsewhere, Army advisory missions assisted nations under threat from communism to build up their militaries, usually along American lines to defend against conventional threats but often without the firepower and logistical structure to make them effective.

Even though the American public was perhaps more accepting of the idea of a sizable peacetime military establishment, the Army faced many problems. Strategic planners warned that the next conflict would not allow the lengthy mobilization that the nation had enjoyed during the two World Wars. A standing army might be a necessity. Yet, the drawdown left the service with 10 understrength divisions, and a 1947 study found that the Army could rapidly deploy two divisions only by disrupting its entire recruitment and training system. Budgets also slashed research, development and procurement so far that, by 1950, the Army was relying on old World War II equipment. Combat readiness declined, and air-ground cooperation deteriorated, particularly with the independence of the Air Force, as all of the armed services were reduced to mere sub-departments under the Department of Defense. The Army was unable to convince Congress to institute universal military training; in 1948, it had to settle for a renewal of the draft. Finally, the Army had to justify its role in an age when the atomic bomb seemed to have changed everything about warfare. War plans left little room for the Army beyond serving as a guard for advanced air bases and as an occupational force once the Air Force had devastated the enemy with atomic weapons. Deterrence through the bomb seemed the best and most economical way of ensuring national security.

The Korean War

Then the Cold War suddenly turned hot. On 25 June 1950, communist North Korea attacked across the 38th parallel into South Korea. Within days, President Truman directed General MacArthur in Japan to send in American troops. Truman at first sought to restore the status quo in Korea, but he and his advisers suspected the attack to be only part of a Soviet design to divert the United States prior to launching an offensive on Western Europe. Thus, as they began partial mobilization, they sent four divisions to Europe, raising American strength there from 80,000 to 230,000. The Army brought its deployable divisions up to strength by stripping personnel from the rest of the Regular Army. It called up eight National Guard divisions and recalled reservists. In Korea, the Eighth Army finally halted the North Korean advance at the Pusan Perimeter and, aided by an amphibious assault deep in the enemy’s rear at Inchon, drove the communists in a rout back across the 38th parallel. Success led Truman to expand his goal to seek reunification of the Korean peninsula, and MacArthur sent his United Nations (UN) forces headlong toward the Yalu River, the boundary between China and Korea. After repeated warnings, in November, the Communist Chinese intervened in force, sending UN forces in retreat back down the peninsula. Lieutenant General Matthew B. Ridgway rallied the Eighth Army and drove the communists back to the parallel. At that point, Truman, concerned about escalation to a World War III, refused MacArthur’s appeals to expand the war into Manchuria or to use atomic weapons, and he returned to his original goal. When MacArthur protested publicly, Truman relieved him in April 1951.

For the next two years, the struggle remained a stalemate as the two sides negotiated and the American public adjusted to the idea of limited war. The Eighth Army fought a war of attrition, position and firepower, conducting only limited offensives and minimizing casualties. Within the Truman Administration, strategists debated whether to resume the offensive, retaliate directly against the Chinese communists or otherwise expand the war, but they were not ready to risk another global conflict so soon after the last one, particularly given the cautious views of UN allies. Many Americans, and some military leaders as well, were outraged that the country was not using its full resources to achieve a decisive victory. Officers at the front faced the problem of maintaining morale and aggressiveness among soldiers enduring extreme weather in rugged terrain while waiting for a settlement. Since the nation did not fully mobilize, serious questions arose at home over who was to serve, as only a few states sent their National Guard divisions, and individual reservists who had fought in World War II protested their callups for another conflict. In 1951, the Army instituted personnel rotation, which helped morale, but it also negatively affected unit cohesion, and personnel issues finally forced the service to implement the desegregation that Truman had ordered in 1948. With an armistice in July 1953, the UN forces accomplished their original mission of preserving South Korea, and the war had shown that ground forces were still important in warfare. But the conflict left a bad taste for Americans, especially when claims of collaboration with the enemy by American prisoners raised questions about toughness in American culture.

A new president, Dwight D. Eisenhower, had to make strategic choices in the aftermath of the Korean War. Containment now applied to Asia, as the United States formed a ring of alliances around Communist China. But the nation could not intervene militarily in every Korea-type situation. It had to conserve its political, economic and moral resources for what Eisenhower called “the long haul.” Given the immense human and material assets of the Communist Bloc, efforts to equal it in conventional forces would bankrupt the nation. For the moment, Soviet nuclear capabilities did not match those of the United States. Therefore, Eisenhower adopted the “New Look,” based on massive retaliation with nuclear weapons against communist aggression at times and places of American choosing. The New Look increasingly stressed advisory training of foreign militaries, which hopefully would make U.S. intervention, particularly by ground troops, unnecessary. To handle contingencies at the lower end of the conflict spectrum, Eisenhower resorted to psychological warfare, Marine landings and covert operations by the Central Intelligence Agency. Aside from the advisory mission, this left little room for the Army, which argued that nuclear weapons could not deter every aggression. As the economy-minded Administration slashed defense budgets, the services competed for dollars, missions and other resources. The Air Force, as the principal delivery system for nuclear weapons, usually emerged as the winner, with the Army as the loser.

The 1950s were hard years for the Army. A new wave of security intellectuals in universities and think tanks debated strategic warfare, game theory and nuclear scenarios. Attention focused on sleek, new weapon systems such as ballistic missiles, B-52 bombers and nuclear carriers and submarines. As the least glamorous service, the Army found it difficult, even with the draft, to find the skilled technicians it needed for its increasingly complex weapons and communications. The officer corps suffered from a career management system that encouraged ticket punching, conformity and managerial over warrior skills. Junior officers left the service in droves. Between 1953 and 1960, the Army shrank from 1.6 million troops to 860,000, and from 19 to 16 active divisions, many nondeployable. Just as the 19th-century Army focused primarily on the frontier, the 1950s Army looked to Europe for a purpose. To deter a Warsaw Pact offensive, but also to make the service look relevant in the nuclear age, the Army explored the idea of tactical nuclear warfare, developing atomic missiles and shells for its artillery—and even its infantry—and introducing a Pentomic division of five battle groups that would disperse to avoid nuclear targeting, then reconcentrate to attack. To World War II veterans, these munitions, while highly destructive, just seemed to be a bigger bomb and thus usable. Field exercises, however, soon showed the new division to be too dependent on other organizations for firepower and logistics and to possess inadequate technology—such as updated armored personnel carriers and radios—critical for the tactics necessary. Introduction of nuclear scenarios soon reduced such exercises to utter chaos.

By 1961, the strategy of massive retaliation had become untenable. The lack of response to the Hungarian uprising in 1956 showed its impotence, and the launch of the Sputnik satellite in 1957 raised the specter of the Soviets nearing nuclear parity or even superiority. Tactical nuclear warfare lost credibility as its inherent chaos and uncertainty regarding escalation became apparent. Furthermore, the Cold War was expanding into the so-called Third World as communists supported “wars of national liberation” in weak, underdeveloped countries emerging from decolonization. Insurgents around the world were using Mao Tse-tung’s ideas on revolutionary warfare to undermine regimes friendly to the West. The Army had long pointed out the need for an ability to respond across the conflict spectrum at the appropriate level of force, a concept known as flexible response, and its primary advocate, General Maxwell D. Taylor, became influential when President John F. Kennedy took office in 1961. Although the new Administration revealed that concern over Soviet missile superiority was misplaced, it increased defense budgets to build conventional and unconventional forces that could win wars without resorting to nuclear weapons. As nuclear weapons became unusable for anything other than deterrence, strategic thinkers posed limited war theories, restricting such wars to concrete, well-defined goals that did not call for full military effort or total victory. Through a graduated response at different force levels, it might even be possible to signal resolve that would lead an adversary to back down, a method that the Cuban Missile Crisis of 1962 seemed to justify.

Flexible response sparked a renaissance in the Army of the 1960s. The service added two new divisions and expanded to 970,000 men. It deployed strong forces in Europe, Korea and Japan while maintaining a mobile strategic reserve in the United States. It refocused on conventional combat and converted from Pentomic formations to Reorganization Objective Army Divisions (ROAD), consisting of flexible, brigade task forces that could fight in any environment with greater conventional firepower and better tactical mobility. It introduced new tanks, rifles, armored personnel carriers, missiles and helicopters for transportation, evacuation and fire support. Based on the Howze Board’s vision of air mobility, the new 1st Cavalry Division could maneuver and attack entirely with helicopters, a capability for conventional warfare, but one that the Army felt would be especially useful against guerrillas. Responding to communist-backed wars of national liberation, the Kennedy Administration pushed the Army to do more in the fields of special warfare and counterinsurgency, and the Army published new manuals, taught more courses and expanded Special Forces, the “Green Berets.” Most Army officers, however, believed that any good soldier, with decent intelligence and a manageable political situation, could handle guerrillas. American advisers trained foreign troops in counterinsurgency tactics. Meanwhile, the Secretary of Defense, Robert S. McNamara, was instituting broad reorganizations and new planning and management procedures, including a stress on quantification, to make the services more efficient. He also streamlined and rationalized the reserves to improve readiness. The Army that went into Vietnam was larger, better equipped, and better trained than its 1950 counterpart.

The Vietnam War

The fledgling Southeast Asian country of South Vietnam presented a test case of the American ability to resist communist wars of national liberation. Fearful that the loss of South Vietnam would have a falling domino effect on the region, Eisenhower had provided aid and advisers to Ngo Dinh Diem’s regime after the Geneva Conference of 1954 divided Vietnam into a communist North and a Western-aligned South. After agreeing to neutralize neighboring Laos in 1962, Kennedy felt he had to draw the line in South Vietnam, and he greatly expanded American assistance, including providing helicopters, to fight the Viet Cong insurgents and North Vietnamese infiltrators seeking to overthrow Diem. The American advisory command developed training facilities and distributed thousands of tons of equipment to form a conventional South Vietnamese Army that could repel an attack from the North and deal with guerrillas and subversion. In the rugged Central Highlands, Special Forces armed and trained Montagnard tribesmen to defend their villages and hamlets and to counter infiltration along the border. But after some progress in 1962, the war took a bad turn in 1963, as opposition to Diem’s authoritarian government skyrocketed, especially among the Buddhists, who accused Diem of favoring his Catholic co-religionists. The crisis alarmed Americans because it created an opening for the communists, and Diem resisted their advice to resolve it through compromise and reforms. An American-approved military coup that overthrew Diem in November 1963, three weeks before Kennedy’s assassination, drew the United States even more deeply into the quagmire.

In mid-1965, after a year of chaos and communist gains, President Lyndon B. Johnson ordered American ground forces to Vietnam. The goal was clear enough—the preservation of South Vietnam—but the commitment stayed vague and open-ended. Air power seemed to offer an easy, cheap way of conveying American resolve, as a naval blockade had done in the Cuban Missile Crisis, but the strategy of gradually escalated bombing of North Vietnam did little to sway the determined enemy. Haunted by the legacy of the Korean War and the unwanted escalation it had produced, Johnson would not send large ground forces beyond South Vietnam’s borders. The only option was a defensive strategy to protect a nation with a 1,000-mile border layered with jungle and mountains, ideal terrain for infiltration from sanctuaries in Laos and Cambodia. Furthermore, the threat consisted of guerrillas and regular forces armed by the Soviets and Chinese, creating a dilemma between pacification and population control versus large-scale conventional operations. To keep American participation limited, Johnson would not call up the reserves, stretching Army resources to the limit. General William C. Westmoreland implemented a dual strategy of pacification and attrition to pin down large enemy formations and inflict enough losses to force him to negotiate or abandon his efforts. But the communists kept the initiative in the field, since they usually could avoid combat except in situations of their choosing. To support its activities, the Army developed a huge logistical infrastructure in the underdeveloped nation. As in Korea, individual rotations spread the burden of service but hurt unit cohesion and forced repeated tours for regulars. Troop levels rose until, in 1968, 536,000 American troops were in Vietnam.

At home, the anti-communist consensus, based on the wartime mentality that had largely shaped public opinion since 1941, had begun to unravel in the societal upheaval of the 1960s. In a huge, mostly comfortable, but increasingly diverse and skeptical country, many questioned old-school patriotism, mainstream religions, traditional values and faith in science and technology. A revived romanticism and hunger for new certainties rebelled against the hard, pragmatic culture of corporations, universities and the military as insensitive and exploitative. The Army’s managerial indices of success in Vietnam, such as body counts, did little to dispel such criticism. African and Mexican Americans, women, gay people and Indians all protested their station in American life, and the resulting domestic disturbances—starting with Little Rock in 1957, Mississippi in 1962 and Alabama in 1963—often required intervention by regulars and the National Guard to restore order. The war fueled further polarization as enraged nationalists called for America to use its full power in Vietnam, liberals expressed concern over the diversion from problems at home to assist a repressive regime, and radicals argued that the war confirmed that the United States was a racist, imperialist and militaristic oppressor. The widespread destruction in South Vietnam, the country that this violence was supposed to save, and atrocities such as the massacre of Vietnamese civilians at My Lai made the Army appear inept and bloodthirsty. Although the Vietnam draft was more egalitarian than its usual portrayal, it still raised issues of fairness in a shared burden. The Army’s societal contributions in such areas as space, communications and transportation did little to dispel its growing negative image.

The turning point came with the Tet Offensive in February 1968. The countrywide communist general offensive was decisively defeated by allied forces, which inflicted 50,000 casualties and permanently weakened the Viet Cong. Yet, the mere fact that the enemy could still attempt such an ambitious offensive undermined public confidence in the Defense Department and the White House, which had insisted that the communists were on the verge of defeat. A new president, Richard M. Nixon, attempted to achieve a “peace with honor” by maintaining diplomatic and military pressure on the communists while building up the South Vietnamese Army to be able to continue the fight on its own, a process known as Vietnamization. In the summer of 1969, Nixon began the gradual drawdown of U.S. forces from Vietnam, while General Creighton W. Abrams continued Westmoreland’s combination of conventional operations and pacification. Military success allowed some American units to participate more fully in population control and pacification, but the enemy remained resilient. Believing that victory was unattainable unless they could isolate the South from external interference, the allies launched incursions into Cambodia and Laos in 1970 and 1971 to destroy enemy sanctuaries and to curtail further enemy reinforcement by cutting the Ho Chi Minh Trail from North Vietnam. These initiatives enjoyed only partial success. By 1972, the South Vietnamese Army had become one of the largest, best-equipped forces in the world, but it was still plagued by desertion, poor morale, incompetent leaders and overreliance on American air, artillery and logistical support. After the United States withdrew the rest of its forces in 1973, it took only two years for North Vietnamese regulars to overrun the South.

The Volunteer Army of the Post–Industrial Age; 1973–1991

Defeat in Vietnam only added to the troubles of the United States in the early 1970s. The Watergate scandal and President Nixon’s resignation in 1974 fed cynicism toward American politics and leadership. The country was beginning its post-industrial transformation from a mass production economy to service industries. Stagflation, trade imbalances, energy crises, racial tensions, crime, drug abuse and demographic and social changes rocked the nation. Social critics talked of society’s fragmentation into diverse clusters with little sense of cohesion or responsibility. These factors influenced popular views on warfare and the military. After Vietnam, warfare had lost much of any legitimacy it still had as a heroic endeavor or rite of passage in a righteous cause. Realists called for intervention only in cases involving major American interests. Liberals tried to restore idealism as the driving force of American foreign policy and warned of the power of the military-industrial complex. Nationalists demanded intervention only where the country would use its full power to win. Almost everyone agreed that the nation must be more selective in future military deployments and must avoid protracted wars. The Nixon Doctrine responded that, going forward, the United States would advise and help Third World nations threatened by communism but not necessarily send ground forces. The only region where the Army retained a legitimate role was Europe; some Americans were only willing to send troops abroad to defend Canada. As for the military, Vietnam veterans were plagued by negative images as baby killers, drug addicts and suicidal misfits, and some Americans even disdained professional soldiers as morally suspect.

For professional soldiers, the 1970s became the decade of the “Hollow Army,” which they derided for its low morale, poor discipline and lack of military effectiveness. Many believed the Army had not lost the Vietnam War but had been stabbed in the back by interfering civilian leaders, unscrupulous reporters and a naïve, irresolute public. Some officers argued that the Army should have devoted more attention to pacification and counterinsurgency than to fruitless search-and-destroy missions, but others contended that the Army spent too much time on nation building and should have struck at either North Vietnam or at the enemy supply line through Laos, sealing off South Vietnam for its own army to pacify. To assure a proper strategy in the future, these officers felt, they must be more assertive with the political leaders who had no military experience.

The problems these officers faced in the Army of the 1970s were real enough. Toward the end of the war, as the prospect of victory diminished, discipline had broken down in many units, especially in rear base camps. Racial tension and even attempts at assassination of officers showed the decline in morale and unit cohesion. More than a few soldiers returned from Vietnam as drug addicts. These problems soon spread through the Army, including Europe, where the service had drained resources to support the war. Bad housing, decrepit facilities, worn-out equipment and inadequate training further hurt morale. Officers were also uncomfortably aware that in Vietnam, some had put their career interests ahead of self-denying actions for the good of the service. In mid-1973, the draft came to an end, and the Army initially found it hard to attract quality recruits. 

For the first time in 25 years, the Army consisted entirely of volunteers. To attract recruits, the service eased some disciplinary standards and rules on grooming and reduced the menial tasks that enlisted soldiers had to perform. Advertisements offered skills and benefits and told potential recruits that “Today’s Army Wants to Join You.” The Army also sought more women for a variety of positions that did not involve combat, and it integrated them as individuals, abolishing the separate Women’s Army Corps in 1978. For the first time, in 1976, women entered West Point. More quickly than many anticipated, the Army was able to meet its recruiting quotas by 1974, although it soon again encountered shortfalls. The smaller size of the Regular Army in the post-Vietnam era helped recruitment, but so did bonuses for critical skills and combat arms and incentive payments for recruiters. The nature of the Army changed to a smaller, more diverse group of well-trained, proud professionals who relied less on mass and sheer firepower and more on skill, maneuver and precision weapons. Because more soldiers were long-serving full-timers, care of their families became a much more important consideration for the service. Yet, the change also meant that the Army and other armed services were forming their own cluster separate from the society they served, and that they were able to fight short, intense wars without popular involvement—an arrangement similar in some ways to monarchical armies of the 18th century.

Recognizing this trend, the Army placed more reliance on the reserves for any major deployment. In part, this move represented a backlash to President Johnson’s decision to fight the Vietnam War almost entirely without mobilizing the reserves. In 1970, Secretary of Defense Melvin R. Laird instituted the Total Force, by which the Army, in 1972 and 1973, shifted most combat support and combat service support missions to the reserves. Reserve roundout brigades became an integral part of later deploying active Army divisions. In 1976, the president received the authority to call up reserves for up to 180 days without congressional approval. These steps allowed the active army to increase from 13 to 16 divisions as a ready force for the defense of Europe and short-term contingencies.

The defense of Europe drove the rebuilding of the post–Vietnam Army. In part, this effort responded to Soviet modernization and to American policy that Europe was the one place where the national interest could dictate another big ground war. But the Army also focused on the war it wanted to fight, the most dangerous contingency on the spectrum aside from nuclear conflict, if also the least likely. High-intensity conventional war in Europe of the World War II type would allow the Army to exploit its strengths of mechanization and technology, but, given the sheer size of Warsaw Pact forces, it had to adjust its training and doctrine to be able to fight outnumbered and win. The Yom Kippur War of 1973 in the Middle East was short, intense and lethal, and it also showed that new antitank weapons and surface-to-air missiles might strengthen the defense against tanks and aircraft. Above all, the new scenarios of a short war highlighted the centrality of readiness and winning the first battle. In the 1970s and 1980s, the Army and Air Force evolved Air Land Battle doctrine, under which NATO would respond to a Soviet offensive by seizing the initiative and rapidly maneuvering its armored forces to inflict blows from unexpected directions, while the Air Force attacked rear echelon elements in the deep battle. To carry out this doctrine, the Army developed five weapons systems: the Abrams tank, the Bradley infantry fighting vehicle, Apache and Black Hawk helicopters and the Patriot missile system. The new approach required a high degree of competence in combined arms, and the Army instituted better, more realistic training, such as the National Training Center, where units maneuvered in the desert against a trained aggressor force. In the process, lower-intensity conflict received much less attention.

The Army’s rebirth received a major boost from the conservative revival of the late 1970s and 1980s. After a decade of détente, the Soviet Union invaded Afghanistan in 1979 and threatened Middle Eastern oil. President James E. Carter responded with sanctions and a military buildup, but the debacle of the hostage rescue mission in Iran embarrassed the nation and contributed to the election of Ronald W. Reagan. Reagan rode into office on the fears that the country had fallen under the rule of an intellectual, liberal elite that had mismanaged Vietnam and rejected patriotism. Christian nationalism rose as many evangelicals saw American security and the final achievement of Christ’s saving mission as closely related. Among middle-class males grew a paramilitary ethos that celebrated the hard, individual male warrior as a hero betrayed by his government. Popular culture, such as Tom Clancy novels and the films Rambo and Top Gun, revolved around military themes. Conservatism shifted from realism to a messianic nationalism that saw the world as a struggle of good versus evil, with the Soviet Union as the Evil Empire. Reagan bathed his Administration in military imagery as no president had ever done, while accelerating the military buildup and showing his strong regard for servicemen. Vietnam became a noble cause, undermined by an un-American elite. In practice, Reagan was more of a pragmatic realist, restrained in his use of force and willing to negotiate reductions in nuclear arms with the Soviets. He responded to fears of nuclear warfare with a missile defense system, another expression of American faith in technological wizardry and belief that the nation could be absolutely safe from attack.

How would the country use this rejuvenated military? The State Department wanted the American military to be an active extension of American foreign policy. But in November 1984, Secretary of Defense Caspar W. Weinberger and his military assistant, Brigadier General Colin L. Powell, laid out what came to be known as the Weinberger/Powell Doctrine, which reflected the views of many Army officers in the wake of Vietnam. The statement laid out criteria for the use of American forces in war, stating that the United States should commit its servicemen only for vital national interests that had the whole-hearted support of Congress and the people, that it should have a clear definition of objectives and that it should only go to war as a last resort. If the nation were to use force, it must apply overwhelming, decisive power in a minimal time to ensure victory. In effect, the doctrine tried to define the only type of wars that the country and its Army would fight, leaving out several contingencies that might demand military involvement short of total victory. Along with the Army’s dependence on the reserves for any major deployment, the document reflected the post–Vietnam Army’s distrust of its civilian leadership.

As events proved, other types of conflicts would test the Army of the 1980s. Operation Urgent Fury, the intervention in Grenada in 1983, showed the multiple deficiencies of the services in joint planning, doctrine and communications, but soldiers and Marines used airborne and amphibious assaults and overwhelming firepower to defeat a second-rate opponent. In El Salvador, where Marxist revolutionaries challenged the Western-aligned government, American aid in the form of advisers, psychological operations and six billion dollars did not achieve victory for the Salvadoran armed forces, but it did prevent their defeat. In Colombia, 800 troops, 600 contractors and seven billion dollars were used against revolutionaries. The Army supplied personnel for multinational peacekeeping forces in the Sinai and Beirut during the decade. In December 1989, 28,000 soldiers and Marines overran Manuel Antonio Noriega’s drug trafficking regime in Panama. The chronic problems of joint operations led Congress in 1986 to pass the Goldwater-Nichols Act, which strengthened the authority of the chairman of the Joint Chiefs of Staff and the geographic unified commands and put more stress on joint training. Special operations forces (SOF)—Rangers, Special Forces, psychological warriors, civil affairs specialists and a dedicated aviation unit—received a higher priority, as Congress created a joint unified command for all service SOFs. During the early 1980s, the Army also introduced light infantry divisions, which were supposed to deploy quickly and handle small wars and contingencies in difficult environments, but still had basically a conventional organization, training and doctrine.

Then, suddenly, the Cold War—around which the reformers had built the new Army—came to an end. On 9 November 1989, Berliners celebrated the fall of the Berlin Wall, which for 28 years had symbolized the division of Germany and Europe. Over the following months, Soviet power in Eastern Europe collapsed as Soviet troops left the former Warsaw Pact regimes, whose communist-dominated governments were replaced by democratic states. On 25 December 1991, the Soviet Union itself dissolved. For those Americans for whom the Cold War was an established fact of existence, the spectacle was exhilarating. Vietnam became just one setback in a long struggle from which the United States had emerged victorious, again the light of the world. It seemed the nation, the lone surviving superpower, now had the freedom of action to use its unrivaled strength to spread its liberal values throughout the world.

But just as Americans were absorbing these events, trouble erupted in the Persian Gulf. For years, the Middle East and its oil reserves, on which Western economies were so dependent, had become a source of increasing strategic concern for the United States. President Carter had created a Rapid Deployment Force to defend the oil fields from any Soviet incursion. When Iraqi dictator Saddam Hussein’s forces overran oil-rich Kuwait in August 1990, President George H. W. Bush declared, “This will not stand,” and deployed, successively, two full corps and two Marine divisions, while assembling large coalition forces to drive the Iraqis from the country. This time, American strategists took care to set clearly defined, limited objectives—the liberation of Kuwait and destruction of Saddam’s forces there—and gathered an overwhelming force to achieve it, but without mobilizing a full national effort. While 75,000 reservists deployed to the theater, the National Guard roundout brigades did not go overseas; instead, they trained while the Army substituted regular formations. As tensions rose during the fall of 1990, so did American anxiety. The Iraqi Army in 1990 was a highly respected, combat-experienced fighting force of over a million soldiers under full mobilization. Although the U.S. Army had largely recovered from the Vietnam experience in terms of doctrine, technology and training, its prospects in a major conventional war were still uncertain. Many worried about a costly, protracted war in rugged terrain and climate without popular support.

They need not have worried. On 17 January 1991, Operation Desert Storm opened with massive air and missile strikes throughout Iraq. In the first weeks of the war, the coalition relied heavily on its air forces to weaken the Iraqi defenders, and the airmen inflicted enough damage to claim later that they had actually won the war. When General H. Norman Schwarzkopf’s coalition ground forces finally took the offensive on 24 February, they severely overmatched their Iraqi adversary in technology, training, doctrine, leadership and morale. While the Marines and coalition forces pinned down enemy forces along the Kuwaiti-Saudi border, the VII and XVIII Airborne Corps drove around the Iraqis’ western flank in an enormous turning movement that disrupted enemy communications and forced Iraqi forces into the open, where they could be destroyed by coalition air and armor. The offensive was not without flaws. Problems of air-ground coordination, fratricide and poor maps hampered operations, and the much-acclaimed Patriot antiaircraft missile system actually achieved only mixed success against Iraqi Scud missiles. Schwarzkopf found it hard to coordinate his corps, and while the coalition inflicted severe damage on Saddam’s Republican Guard along the “Highway of Death,” most Guard units escaped to fight another day. Although Desert Storm freed Kuwait at relatively low cost—only 150 American and 99 coalition dead versus over 20,000 Iraqis dead and 50,000 other casualties—Saddam and his army remained a regional threat. After the post-Vietnam years, the war represented validation for the Army, but it fostered an overestimation of American military capabilities and willingness to use them.

Searching for an Identity in the Post–Cold War Army: 1991–2025

A Global Constabulary

If anything, the end of the Cold War brought more turmoil into the world order. The breakup of bipolarity revived old hatreds and rivalries among tribal, religious, ethnic and national groups around the globe, notably in the Balkans and the Middle East. Furthermore, global interaction and new technologies enabled individuals and groups that shunned the tolerance and pluralism of the liberal order to achieve an influence and destructive capacity out of proportion to their size. Population growth and a surplus of arms in the developing world as a result of Cold War proxy conflicts fed rising tensions. More states had the capability to develop nuclear, biological and chemical weapons.

The United States itself was changing in the 1990s. On the one hand, the nation in many ways had become a much more open, diverse society. On the other, it was increasingly divided into groups characterized by differing social classes, income levels, races, ethnicities and values. With the all-volunteer armed forces, the armed services performed less of a homogenizing function. Fewer Americans had experience with the military or with warfare. Liberals who backed President William J. Clinton shared the nationalist view that the nation had a special responsibility to lead and inspire the world, but their patriotism emphasized diversity and tolerance at home and cooperation and commerce to promote free markets, human rights and democracy abroad. They often distrusted military institutions but were prepared to intervene in the name of humanity in the strife-torn post–Cold War world, tempering the use of force with restraint and aware of popular intolerance for heavy American casualties. Critics complained that this “neo-liberal” approach to foreign policy put too high a priority on international institutions and the global economy at the expense of traditional sources of national unity and purpose.

And so it was that, with the end of the Cold War, the Army faced an identity crisis. Losing its core mission against the Warsaw Pact, the Army faced pressure from political leaders for a “peace dividend” that would reduce forces and cut expensive weapon programs. Between 1989 and 1996, the Army shrank from 770,000 to 500,000 troops. Large numbers of soldiers departed from Europe. A series of defense reviews inactivated six divisions and provided for a much smaller overseas force, backed by a contingency corps in the United States. After Desert Storm cast doubt on the Total Force concept, the Army stopped short of eliminating National Guard divisions, but instead emphasized the readiness of 15 enhanced brigades that could deploy within 90 days of mobilization. Doctrine still stressed decisive victory through maneuver and joint/combined operations, but it now defined the role of the Army as a deterrent across the conflict spectrum and as having the capacity to project power quickly around the globe. In the wake of Desert Storm, the ability to deploy fast to overseas theaters became a major consideration, requiring a lighter, more mobile force and prepositioned bases in regions such as the Middle East. This raised questions about the ongoing value of heavy divisions, especially in an era of precision weapons and airpower. The Army’s culture was also changing. By the end of 2000, 42 percent of recruits came from the South, and the numbers of women and minorities were rising sharply. The increasing number of families had implications for base housing and other benefits. A restive junior officer corps criticized the perfectionism and careerism of their superiors. More politically conscious than in the past, many felt superior to the society they had pledged to defend.

Part of the restiveness within the Army came from its ever-increasing tempo of activity. Recognizing the immense capability of the armed forces, political leaders turned to them to perform missions that civilian agencies could not do. These complex efforts often involved cooperation with non-governmental organizations (NGOs), host countries and several other actors. These efforts also required restraint, perseverance and continuous and open communication with the public. Some assignments were conventional military missions, such as guarding the demilitarized zone in Korea or periodically deploying to Kuwait to deter Saddam Hussein, but peacekeeping, contingency operations, counterterrorism, drug interdiction, disaster relief and other tasks bearing such labels as “low-intensity conflict” or “operations other than war” transformed the Army into a quasi-global constabulary. Army engineers reconstructed Kuwait, and Operation Provide Comfort aided the Kurds in northern Iraq. Army helicopters and paramedics assisted victims of earthquakes, floods, hurricanes, famines, oil spills and forest fires. And, with the increasing threat of international terrorism, soldiers guarded facilities and trained American and foreign law enforcement personnel. Multiple deployments taxed soldiers and their families, and the Army turned to the reserve components, which evolved from a strategic reserve, available in the event of a major war, into a rotational force that went through repeated call-ups for missions short of a major conflict. The Army did little to adjust its doctrine or force structure to these unorthodox operations, relying on ad hoc training and the ingenuity and adaptability of its soldiers to adjust as situations arose.

Four operations stand out from this era. Beginning in December 1992, 13,000 soldiers and Marines joined a multinational task force that cowed warring factions in Somalia into allowing delivery of over 40,000 tons of food to a starving population. But the force soon became embroiled in clan politics, resulting in an October 1993 strike in Mogadishu by Army Rangers that captured high-level leaders of the Aideed group but encountered intense Somali resistance that downed two Black Hawk helicopters and killed 18 Americans. Five months later, President Clinton withdrew the remaining troops. The Army again had to improvise in an urban environment when, in July 1994, a UN resolution authorized member states to use all necessary means to convince the Haitian military government to restore democratically elected President Jean Bertrand Aristide to power. After landing on Haiti in September, for six months American troops tried to maintain order, guarded foreign interests, gave technical assistance and training to the Haitian Army and police, and supervised Aristide’s return. In Bosnia-Herzegovina, torn by ethnic strife after the breakup of the former Yugoslavia, a cease-fire in August 1995 was enforced by a NATO-led Implementation Force (IFOR) that included 20,000 American troops who marched overland from central Europe to take up their zone in northern Bosnia. IFOR separated the two sides, removed mines, rebuilt houses, resettled refugees and supervised new elections. When NATO air strikes forced Serbia to give up its attempt to drive ethnic Albanians out of the province of Kosovo in 1999, the United States contributed a brigade of 7,000 troops to help keep the peace.

Yet, even as the Army engaged in numerous interventions involving complex political and cultural factors, it maintained its intense focus on technology and high-intensity conventional operations. The 1990s witnessed an information revolution, as computer networks began moving enormous masses of data quickly and accurately. Together with satellites and the rise of Global Positioning System (GPS), modern communications, advanced guidance systems, sensors and developments in lasers, plastics and light metals, these developments led many to proclaim a Revolution in Military Affairs (RMA) that promised an enhanced ability to detect, track and engage multiple targets simultaneously. Every Army leader would have real-time battlefield visibility, preventing fratricide, and precision weapons would increase the rate and accuracy of firepower. The RMA would ostensibly make possible leaner, more lethal, more nimble, joint task forces that could achieve “full spectrum dominance” over any prospective enemy, using the latest technology, operated by a few skilled technicians.

Under the leadership of General Eric T. Shinseki, who took over as chief of staff in June 1999, “transformation” of the Army accelerated. The Army faced a dilemma; its heavy divisions were too bulky to deploy quickly, but its light units lacked staying power against any real adversary. It converted its divisional brigades into autonomous brigade combat teams, each with its own logistical support units and independent resources that could generate more firepower than the old formations. It would equip these units with smaller, air-transportable vehicles. The wheeled, lightly armored Stryker gave its name to some of the rapidly deployable brigades. For the eventual “Objective Force,” the Future Combat System (FCS) would have manned and unmanned reconnaissance, troop-carrying, tank-killing and artillery-mounted vehicles linked by a fast, flexible digital network. But the FCS never came to fruition, and the Department of Defense eventually canceled the Crusader Howitzer system and the Comanche helicopter, leaving the Army to rely on its old, “legacy” systems. As the Army entered a new millennium, it still focused on overwhelming combat power as an end in itself, leaving little room to consider strategic thinking, ideology, religion, culture and other human intangibles in its studies.

9/11 and Its Aftermath

On 11 September 2001, attacks by al Qaeda terrorists on New York’s Twin Towers and the Pentagon killed 3,000 Americans and shook the United States out of its complacency. Not since Pearl Harbor had the nation experienced such a sense of vulnerability. From the start, the Army was heavily involved in the response, as the National Guard provided disciplined, ready troops with special skills to secure federal facilities, transportation networks and nuclear plants and, in particular, assisted New York City authorities with traffic control, medical support and debris removal. With 9/11, Americans found a tangible adversary. Although global terrorism presented a vague, amorphous, transnational target that often spilled over into outrages against Muslims and Arab-Americans, it also inspired a righteous vengeance that overwhelmed old restraints against unilateralism and preemptive intervention. President George W. Bush’s Administration adopted a larger counterterrorism strategy that incorporated diplomacy, intelligence sharing, financial controls, security cooperation with partner states and strikes by drones or special operations forces to kill or capture terrorists in Yemen, Pakistan, the Philippines and Africa. It also assumed presidential power to create military tribunals and incarcerate suspected terrorists at Guantanamo Bay, Cuba.

Within weeks of 9/11, American forces launched the invasion of Afghanistan to topple its fundamentalist Taliban regime and kill or capture the al Qaeda leadership that had sheltered there. The mission was one of the first tests of Defense Secretary Donald H. Rumsfeld’s vision of combining precise and powerful aerial attacks with a minimal ground presence, which made up in air support and mobility for its lack of mass. Special Forces teams deployed by helicopter to anti-Taliban resistance bases to cooperate with those forces, using their sophisticated communications, navigation devices and laser designators to call in air strikes with precision munitions. By January, the anti-Taliban fighters had broken out of their enclaves in the north and had overrun most of the country, but al Qaeda and Taliban leaders escaped to Pakistan, perhaps with the collusion of resistance leaders who did not answer to American authority in the way regular units would have. In Bonn, Germany, a special conference of regional powers and Afghan groups, excluding the Taliban, reached agreement on an Afghan Interim Authority that would rebuild the country and set the stage for a new government. While a multinational UN force secured Kabul, American troops, Afghan allies and special operations forces from five other nations drove into the rugged mountains along the Pakistani border, fighting in terrain up to 12,000 feet above sea level. During Operation Anaconda in early March 2002, coalition troops found an unexpectedly large Taliban force in well-defended mountain positions and cave complexes with huge stockpiles of ammunition. It took hard fighting, including risky air assault landings on ridges in inclement weather, to overcome problems of overloaded communications and sporadic close-air support. Still, the Army seemed to have accomplished its mission of overthrowing the Taliban.

By the summer of 2002, however, the Bush Administration was turning its attention from Afghanistan to Iraq. Since Desert Storm, Saddam had periodically threatened another invasion of Kuwait and had obstructed UN inspections for nuclear, biological or chemical weapons. Bush decided an invasion was necessary to remove Saddam from power and destroy or control his weapons of mass destruction, thereby eliminating his threat to the region and, potentially, the United States. The Iraqi Army, although weaker than in 1990, still possessed a sizable force, but Rumsfeld believed that the transformed U.S. Army could easily brush aside Iraqi resistance and withdraw after a short occupation. He cut the invasion force for Operation Iraqi Freedom from 500,000 to 143,000 American and British troops. Starting 20 March 2003, as aircraft and missiles hit strategic Iraqi targets, four coalition divisions drove from Kuwait into Iraq. In northern Iraq, an airborne battalion and Special Forces linked up with the Kurds to divert the Iraqis from the main front, while, to the west, special operations forces raided Iraqi facilities and potential weapon storage sites. Most Iraqi units dissolved or surrendered, but some Republican Guards fought, and guerrilla raids harassed the 400-mile coalition line of supply. At times, the drive stalled as technological superiority counted for less against sandstorms and unexpected Iraqi tactics. But by 3 April, the 3d Infantry Division had reached Baghdad’s outskirts and was conducting “thunder runs”—tank raids—into the city. On 9 April, the coalition occupied Baghdad, and organized resistance ended.

But the war was not over for the U.S. Army. The original plans for a modest reconstruction and quick turnover of authority to a new regime did not recognize the crumbling state of the Iraqi economy, the depth of societal divisions or the resilience and intensity of Saddam’s Ba’athist followers, many of whom lost their positions after the Americans disbanded the army and purged them wholesale from the government. The short occupation that the Army anticipated turned into years of bitter struggle to create a democratic nation-state from a wary Shi’a majority long repressed by Saddam and influenced by Iran, a fearful and resentful Sunni minority, independence-minded Kurds, and insurgents who were out to kill American soldiers and stir up as much chaos as possible. The small invasion force could not be everywhere, and looting and lawlessness were followed by a deepening insurgency for which American troops were unprepared. Even after Saddam’s capture in December 2003, the violence grew. Roadside bombs, mortar attacks and ambushes inflicted casualties on coalition forces and Iraqis alike.

The United States could not just depart and leave a failed state open to terrorist penetration. While a U.S.-led Coalition Provisional Authority (CPA) assumed the task of reconstruction, the Army conducted cordons and searches to find and kill or capture Ba’athists and terrorists. But American soldiers had little training in these sensitive missions, and some of their tactics inflamed the population more than conciliating or reassuring it. Imprisonment of suspects led in the spring of 2004 to the notorious Abu Ghraib scandal, involving abuse and torture of prisoners by American troops. The Army tried to organize and train an Iraqi army and police force that could assume security tasks, but those forces were dominated by Shi’ites and too often rushed into service before being ready. By the end of 2006, about 2,400 Americans had died in Iraq. Although successful elections had installed an Iraqi government, sectarian violence continued to escalate, and the American public feared another Vietnam-type quagmire.

The Army responded to the challenge in different ways, both technological and doctrinal. Facing the threat of improvised explosive devices (IED), the service adapted an old, South African armored car into the Mine-Resistant Ambush-Protected (MRAP) vehicle, using a high-riding, steel-armored, V-shaped hull that directed a blast’s energy out and away from the chassis. It also formed a special aviation task force that used airborne sensors to locate insurgents and bomb sites, and it introduced the Biometrics Automated Toolset, which stored facial and fingerprint data to track suspects among local populations. As the protracted conflict created enormous stresses on soldiers and their families, the Army instituted Army Force Generation (ARFORGEN), a three-stage sequential process by which active and reserve units returned from overseas to rest, reequip and retrain; prepare for their next mission; and redeploy abroad. Indeed, these repeated deployments completed the transformation of the National Guard and Reserve from a strategic reserve to a rotational force for ongoing contingencies. Revised doctrine raised post-conflict stability operations to a level of significance equal to defensive and offensive operations and provided guidelines for counterinsurgency, stressing population control over search-and-destroy tactics.

A more population-centered approach lay at the center of the surge—President Bush’s decision in January 2007 to send five additional brigades to Iraq to counter rising violence. By mid-August, U.S. troop levels in Iraq had risen to 162,000, the highest of the war. General David H. Petraeus, a leader in the counterinsurgency movement, took over coalition forces in Iraq. He and Lieutenant General Raymond T. Odierno, commander of the III Corps headquarters in Iraq, emphasized protecting the population by moving troops from forward operating bases to small outposts within cities, where they established a presence and used concrete barriers, checkpoints and improved intelligence to disrupt extremist activity and uncover arms caches and safe houses. Coalition troops cleared Baghdad of extremists, neighborhood by neighborhood, and conducted incursions into the “belts” around Baghdad, where insurgents had formerly found sanctuary. In al Anbar Province and other parts of Iraq, Sunnis who were unhappy with the insurgents’ heavy-handed political and social order rallied and drove out the terrorists with significant, if cautious, help from their former adversaries. The campaign cost over a thousand American lives, but with enough forces to simultaneously clear and hold large areas, the coalition had substantially reduced violence when it began to withdraw surge forces in late 2007.

As successful as it was in the short term, the surge only bought time for the transition to Iraqi responsibility for security. In late 2008, Iraq and the United States reached an agreement that all American troops would leave the country by 31 December 2011. For the next three years, Army brigades, modified for the mission, and “stability transition teams” focused on training the Iraqi Security Forces and assisted them in their efforts to restore and maintain order. Simultaneously, the Army lowered its presence, returning units to the United States without replacing them and handing over American bases and equipment to the Iraqis. When the two governments could not agree on an ongoing American presence in Iraq, in October 2011, President Barack H. Obama ordered the withdrawal of the remaining American forces by the end of the year.

While focusing on Iraq, the United States had devoted minimal resources to Afghanistan. As in Iraq, policymakers had no appetite for nation-building, but they could not allow another failed state to serve as a haven for terrorists. At the very least, they sought a working national government that would allow for an honorable withdrawal. But the task was daunting. Afghanistan lacked a national identity. It was a divided tribal country of rugged terrain, few natural resources, little infrastructure and a chaotic society that was in shambles after 30 years of warfare. With support from over 50 nations providing everything from combat troops to logistical assistance, American forces concentrated on locating and destroying any residual Taliban and al Qaeda forces left in Afghanistan. Company-sized units joined by special forces and Afghan troops cordoned off and searched villages. Larger formations conducted heliborne assaults against small insurgent bands, inflicting heavy casualties and seizing caches of arms and ammunition. At the same time, in cooperation with the multi-country International Security Assistance Force (ISAF), soldiers sought to create an Afghan National Army practically from scratch in a country with no national military traditions, a lack of facilities and poor pay, resulting in corruption and desertions.

As time passed, the Army was more involved in counterinsurgency, humanitarian assistance and efforts to extend the authority of the interim government. In early 2003, provincial reconstruction teams (PRT) of military, diplomatic and civilian experts deployed into the countryside to carry out reconstruction projects and establish contact with local leaders. These efforts expanded during 2003 to involve several nations and American agencies. Rather than conduct larger-scale sweeps to locate and destroy terrorist bases, each Army unit became responsible for an area, which it would clear and then introduce civil affairs, medical and psychological operations specialists to consolidate the gains. But the total American force in theater seldom ran much above 10,000 soldiers. Even with help from other national contingents, the coalition could not provide sustained security in remote villages and had to cede large areas to the enemy.

That enemy was growing in strength. Regrouping in sanctuaries in Pakistan, various bands infiltrated back into Afghanistan, establishing a presence in the eastern and southern provinces where the coalition was weakest. Taliban attacks increased in 2003, targeting civilians, security forces and NGOs with suicide strikes and roadside bombs to undermine President Hamid Karzai’s government. Many Afghans in remote villages saw the insurgents as more effective than the Kabul regime.

The coalition was slow to recognize and respond to the Taliban revival. Focused on Iraq, American policymakers tried to involve their NATO allies to a larger degree, and in October 2006, ISAF assumed responsibility for security across Afghanistan. But U.S. forces remained independent for training and counterterrorism, and other coalition units had even fewer resources than the Americans and operated under various restrictions from their home governments. The convoluted command structure and wide dispersion of coalition forces made it difficult to develop an overall strategy or any kind of unified effort. To buttress the regime’s authority, commanders pushed units of, at most, platoon size, into forward bases and outposts to disrupt the insurgents and facilitate economic development. Such larger forces as the coalition could muster conducted more major operations and scored some tactical victories. But the Taliban moved to unoccupied parts of the country, built up strength and returned to hit the exposed, remote outposts.

The time was ripe for another surge. Seeking to focus American forces on the “necessary” war in Afghanistan, in 2009, President Obama raised troop levels there to 98,000 to defeat al Qaeda and halt its return to either Afghanistan or Pakistan, but he also set a deadline of July 2011 for a drawdown, by which point Afghan security forces were expected to take on most of the burden. Even with the surge, the coalition’s ability to secure population centers, supply routes and outlying bases and still pursue enemy forces was limited. The Taliban showed more tactical skills in their assaults on isolated outposts, and if they could not resist more sizable coalition operations, they withdrew and waited for the deadline. Despite the surge, training of the Afghan National Army and security forces remained plagued by lack of instructors, high desertion rates, corruption and illiteracy. Many Afghan troops were just trying to escape poverty for their families, a predicament that their death in battle would certainly compound. As the deadline neared, the coalition put more stress on eliminating the insurgency. In May 2011, special operations forces killed Osama bin Laden in Pakistan. By then, al Qaeda had declined to little more than an ideological movement. Still, when in June 2011 President Obama announced the start of the drawdown and handover of responsibility for security to the Afghans, no drastic drop in violence or rise in the quality of Afghan forces had occurred.

 As the Army reduced its presence in Iraq and Afghanistan, new challenges arose on the horizon. After Russia invaded Ukraine’s Crimean Peninsula in 2014, the United States launched Operation Atlantic Resolve, sending soldiers to Eastern Europe to train with NATO partners and support Ukrainian security forces. The rise of the People’s Republic of China impelled American strategists to ensure they had sufficient forces in the Indo-Pacific region to defend allies across southern and eastern Asia, and a Pacific Pathways program expanded combined training and strengthened relationships with Asian militaries. Growing threats in cyberspace led the Army to help form U.S. Cyber Command and increase efforts to defend networks and conduct cyber missions across the spectrum. When the Islamic State of Iraq and Syria (ISIS) established a caliphate that threatened Iraq’s national integrity and Middle East stability in the summer of 2014, President Obama deployed American advisers, who helped rebuild the battered Iraqi Army, assisted in combat operations and directed close-air support that turned the tide. By the spring of 2019, the caliphate had all but dissolved. In 2018, Secretary of Defense James N. Mattis authorized mobilization of the National Guard to assist the Department of Homeland Security with border control, surveillance, logistical support, medical help, communications and engineering tasks while not infringing on civilian law enforcement. 

In Afghanistan, American involvement was winding down to its conclusion. By the end of 2014, the Army’s mission there had devolved to training, advice and assistance for Afghan security forces and institutions, although American forces still pursued al Qaeda remnants wherever they found them. Despite the trainers’ efforts and a surge of 4,000 additional troops in August 2017, the security situation in Afghanistan continued to deteriorate. In February 2020, President Donald J. Trump and the Taliban negotiated an agreement calling for the eventual withdrawal of U.S. forces. As part of the agreement, the American military presence dropped to 8,600 by September 2020, and by July 2021, only about 1,000 remained. By then, the Afghan state was dissolving under the weight of a Taliban summer offensive. In August, Trump’s successor, President Joseph R. Biden, Jr., evacuated over 120,000 Americans and Afghans who had worked with the coalition effort, and America’s Afghan war came to an end.

For the Army, the conflicts of the 21st century’s early years forced some introspection after the triumphalism of the 1990s. The RMA had concentrated on high-intensity warfare and winning battles through technology, but new devices—at least by themselves—could not win the conflicts in Iraq and Afghanistan. Enemies had learned how to fight the United States asymmetrically. More subtle tactics—using infiltration, subversion, guerrilla warfare and basic, cheap technology—left few suitable targets for strikes that might alienate populations. Despite its massive military commitment, the United States often could not induce recalcitrant hosts to make political, social and economic reforms, especially when Americans had little sense for the environments in which they worked. Operations against insurgents or terrorists demanded actual ground forces that could patrol, mingle with the population, gather intelligence, conduct civic action and win firefights. Emphasis on force protection—riding in vehicles, wearing body armor and sunglasses—conveyed the wrong message for engagement. Small unit leaders needed patience and a background in the cultural and social dynamics of their areas before they could provide security. The officer corps had been too busy mastering machines and doctrines to study cultures, languages and human behavior—factors that ultimately led to success in low-intensity conflict. Meanwhile, the regulars and reservists fought the war with little involvement or sacrifice from the rest of American society.

Conclusion

In many ways, the Army of the 2020s faces a similar situation to that of the Army of the 1970s. With the rise of peer competitors in China and Russia, the Army again is preparing for high-intensity, conventional conflicts of the World War II type as it tries to move on from Iraq and Afghanistan. As did Training and Doctrine Command in the 1970s and 1980s, Futures Command seeks to shape the new Army. Once again, as political and racial tensions tear at the fabric of an increasingly diverse society, the Army must recruit a new generation of young Americans to serve and sacrifice. But American foreign policy still insists on the exercise of global leadership, demanding forces ready to deploy anywhere in the world. Thus, the Army will likely again find itself in protracted conflicts involving cultural factors and adversaries that use strategies or tactics to avoid American advantages in firepower and economic capacity. “Multi-domain operations” will demand that the Army compete in many environments with a wide array of means, whether information operations, cyberspace or more conventional joint and combined missions. Reflecting American society, a more diverse and inclusive Army will draw on a spectrum of skills and views. Junior leaders will need critical thinking skills to exercise the initiative and responsibility that 21st century warfare will demand. And the Army must figure out how to use new technologies, from drones, robots and autonomous weapons to engineered and medicated body enhancements, to protect American troops.

For over 50 years, scholars have debated the existence of a unique “American way of war.” Much of the discussion has centered on terms like “annihilation,” “attrition” and “exhaustion.” Some see nothing especially distinctive about the American approach to warfare, finding it well rooted in Western tendencies toward the kind of conventional battles and campaigns waged by large, professional armies typical of European military doctrine. But the U.S. Army has combined common traits in different ways to meet the challenges it has faced throughout its history. In practice, the service has devoted most of its past to low-intensity conflict and “small wars” as a frontier and global constabulary. For the most part, no particular doctrine has driven its approach to these missions. After a difficult start, the Army usually improvises various practical carrot-and-stick responses to guerrilla tactics and subversion. But even since the colonial period, the Army as an institution—regulars and even militia—has been generally inclined toward conventional operations characteristic of the European legacy of its society. It calls on the resources of a vast economy and a large population, and it relies heavily on technology to keep casualties to a minimum. Oddly enough, officers have often used as a model French, Confederate and German militaries that performed well at the tactical and operational level, but have failed strategically. But conflicts across the spectrum call on different, hard-to-acquire and often contrasting skills to meet various contingencies. The Army must balance as best it can preparation for these diverse missions and cultivation of a willingness to adapt and innovate, as almost any type of conflict will raise unforeseen challenges.