Thursday, May 09, 2019

On Dec. 8, 1941, Japan initiated a massive offensive to wrest the Philippine Islands from Allied control just seven hours after attacking Pearl Harbor. The defending U.S. Army and Filipino forces, which had focused on counterinsurgency operations since 1898, remained largely organized, trained and equipped for stability efforts instead of modern large-scale ground combat operations.

While the coalition featured two U.S. Army-led corps with 10 understrength Filipino divisions and a single American infantry division in reserve, the defenders lacked the organizational capacity to enable, employ and sustain integrated fires and combined-arms maneuver across deep and close areas. The hard-fought action, lasting from January to April 1942, resulted in the largest defeat and surrender in U.S. Army history.

The Battle of Bataan should be particularly relevant to the Army as it refocuses on large-scale ground combat operations in the wake of almost a generation spent focused on stability and counterinsurgency campaigns in the Balkans, Iraq and Afghanistan. Those campaigns placed a premium on tactical decentralization and occurred at the same time as the transition to a modular force that in effect de-emphasized the importance of corps and divisions fighting as formations. The lack of peer threats and the demands of continuous deployments allowed the Army to accept risk in areas critical to success during large-scale ground combat.

Significant Capability Gap

The result was a force optimized for limited contingency operations that has significant capability gaps in terms of command-and-control systems, long-range fires, air defense, attack aviation, ground reconnaissance, sustainment, electronic warfare and other areas. In some ways similar to 1941, the U.S. Army’s evolution over the past two decades has ultimately lessened its ability, as stated by Chief of Staff Gen. Mark A. Milley, “to conduct ground operations of sufficient scale and ample duration to achieve strategic objectives or win decisively.” 

Japan’s Philippines offensive occurred as a critical phase in its larger strategy to establish dominance over the South Pacific region. U.S. Army Forces in the Far East (USAFFE), under the command of Gen. Douglas MacArthur, planned to execute War Plan Orange-3 with coalition units from across Luzon converging on the Bataan Peninsula where they would hold until reinforcements arrived. However, the defenders were postured and equipped for limited patrolling operations and unprepared to resource, plan and execute corps- and division-level operations. The Japanese, outnumbered with 75,000 men to the coalition’s 120,000, arrived prepared to execute offensive joint and combined-arms operations learned during years of intense combat in Manchuria.

Japanese forces initiated the campaign by first establishing superiority in air and maritime domains with attacks on poorly defended airfields and U.S. naval elements, and then launching ground forces from intermediate staging bases to seize lodgments at Lingayen Gulf and Lamon Bay. Over a three-month period, the Imperial 14th Army massed heavy artillery, armor, motorized infantry and light infantry units on Luzon while pressuring a costly Allied retrograde, meaning moving back while fighting according to a controlled plan. The invaders eventually defeated the U.S. Army-led I and II Corps on Bataan with a series of attacks that combined superior combined-arms maneuver with overwhelming artillery and close-air support.

Ready for Wrong War

U.S. Army forces in the Philippines entered World War II predominantly manned, equipped and postured for stability operations. The Japanese combined-arms approach found the defenders lacking in armored vehicles, short and long-range artillery, responsive attack aviation, durable sustainment, and flexible command-and-control systems. While the Filipino forces had limited ability to fight at echelon, American commanders and staffs lacked experience, training and communications networks to coordinate deep fires and close combat against modern adversaries.

The sudden requirement to synchronize an echeloned retrograde with converging division counterattacks revealed an army that had not executed corps-level maneuvers since 1918—a period of 24 years. As a matter of reference, the current U.S. Army last executed live full-scale corps-level maneuvers in 1991—more than 27 years ago.

USAFFE’s improper employment and shortages of anti-aircraft systems reflected a second area of disadvantage. U.S. commanders initially prioritized their two air defense regiments to protect southern seaports, which left the northern U.S. Army Air Corps airfields vulnerable to Japan’s initial air and naval attacks. Imperial forces destroyed 75 percent of U.S. aircraft on the ground on Dec. 8 partly because of a lack of adequate early warning systems or preparation, creating untenable dilemmas and cascading disadvantages for Allied forces.

When the command belatedly shifted anti-aircraft systems to protect remaining airfields, it left the hastily entrenched U.S. infantry regiments unprotected across Luzon and then Bataan. The resulting uncontested Japanese air superiority allowed them to decisively shape conditions for follow-on assaults by advancing ground forces.

Inadequate Air Defense

The U.S. Army compounded its problems with inadequate air defense by relying on field artillery that lacked the required range and lethality to shape conditions in forward areas. The defending corps and divisions proved unable to place effective fires on Japanese forces during lodgment, tactical assembly and movement inland. The employment of World War I-era weaponry, compounded by the early loss of air superiority and poor communications, resulted in minimal ability to synchronize fires and maneuver.

The Japanese, in contrast, reinforced their initial forces with heavy artillery and light armor to support infantry assaults. When the Japanese unleashed their largest artillery bombardment of the campaign on April 3, II Corps effectively disintegrated and I Corps was forced to retreat and ultimately surrender.

USAFFE also struggled to coordinate strategy and operations with the U.S. Navy across the larger archipelago. The U.S. Asiatic Fleet, based in Manila and focused on American interests in the South China Sea and Indian Ocean, answered directly to the chief of naval operations in Washington, D.C. MacArthur’s command, however, focused on land operations and exercised only episodic influence over maritime events. This divergence of authorities reduced unity of effort between services. The absence of a unified joint forces commander contributed to a haphazard defense—which was further complicated by destruction of the U.S. Pacific Fleet at Pearl Harbor—and invalidated prewar assumptions that the Asiatic Fleet would be available to more rapidly relieve ground forces in the Philippines.

Allies Underprepared

Another issue that debilitated the U.S. Army’s defense of the Philippines was overreliance on underprepared allies. The Filipino forces, while not lacking in courage, began the war organized and trained for small-unit patrolling with archaic weapons under American leadership. Though U.S. Army generals commanded I and II Corps with integrated staffs, most of the ground combat forces were comprised of Filipino light infantry, with a single American division and critical enabling units in reserve. This led to unrealistic operational plans where higher commands expected lightly equipped and undermanned Filipino regiments to resist the bulk of the Japanese attacks. In actuality, the fatal mismatch of capabilities and planning made the execution of a flexible or sustainable defensive scheme problematic.

Finally, USAFFE lacked responsive logistical systems to sustain aggressive maneuver at scale. Because the Motor Transport Service, under MacArthur’s orders, prioritized moving men and equipment during the retrograde, divisions and regiments abandoned critical supplies in depots across northern and southern Luzon as they converged on Bataan. The lack of tactical distribution capacity created challenges when units adopted the planned multicorps defense and soon exhausted their fuel, ammunition and food stores.

While they should have benefited from operating from interior lines, USAFFE’s failure to enable a flexible sustainment plan to support combined-arms maneuver limited operational endurance and contributed to a decisive Japanese victory.

The catastrophic outcome at Bataan demonstrates the potential risks of not being prepared in terms of organization, equipping and training for large-scale ground combat operations, particularly in contemporary theaters with peer adversaries like in the Pacific and Europe. This means once again optimizing nimble corps and division command posts to control combined-arms operations, employing deep fires with precision and mass to enable maneuver, resourcing responsive sustainment to support dispersed and high-tempo operations at scale, and developing air defense in depth to protect expeditionary forces. Finding solutions for these critical capability gaps is likely to be the difference between defeat and victory on future battlefields.