The U.S. Army is in the process of reorganizing its institutional and operational structure around numbered theater armies. Each theater army will serve as the Army Service Component Command (ASCC) for its respective regional unified combatant command and will report to both Headquarters, Department of the Army (HQDA), and the combatant commander in its area of responsibility (AOR); see figure 1. This reorganization reflects the shift in Army doctrine from threat-based to capabilities-based command structures. In addition to fulfilling their Title 10, U.S. Code, responsibilities to organize, equip and train Army units, theater armies will develop organic, deployable headquarters, giving the Army new capabilities and Source: www.defenselink.mil The new organization will provide enhanced C2 capabilities in the form of a deployable operational command post that can also serve as a Joint Task Force (JTF) or Joint Forces Land Component Command (JFLCC) headquarters with minor augmentation. Additional benefits include improved logistics capability through the TSC, more robust intelligence capabilities in the intelligence brigade, and enhanced planning and regional affairs expertise. Headquartered at Fort Sam Houston, Texas, USARSO has forward operating sites in Colombia and Honduras and supports units in 21 other countries; 1,600 Soldiers are deployed in the AOR at present. Major responsibilities include theater security cooperation, counterterrorism, counternarcotics and disaster relief operations. USARSO also engages in military-to-military cooperation through numerous exercises and through the Conference of American Armies (composed of 20 member armies, five observer armies and two international military organizations, the Conference of Central American Armed Forces and the Inter-American Defense Board).3 Regional Overview The USSOUTHCOM AOR covers an area of 26 million square miles and 31 countries in Central and South America and the Caribbean.4 The Andes Mountains form the western spine of the continent, giving way to the tropical rain forests of the Amazon River basin in the north and the fertile plains of the pampas region in the south. The population numbers some 432 million, composed primarily of the descendants of indigenous peoples, European settlers and African plantation workers, with peoples of Asian descent also prevalent in some countries. The majority of the population speaks Spanish or Portuguese (spoken in Brazil); French, English, Dutch, indigenous languages and even Hindi are also spoken in some areas. Proximity to the region has spurred U.S. involvement on a number of issues, some dating back decades. Currently occupying the central position in U.S. foreign policy is international terrorism, and while Central and South America and the Caribbean are not the main stage for counterterrorism, the region is nevertheless important in preserving U.S. national security. On a parallel track, reflecting the prevailing American view that the Americas are the traditional U.S. sphere of influence, the rising influence of extra-regional actors (especially China) also impacts on U.S. foreign policy decisions. Beyond these global security considerations, numerous issues specific to the region occupy the attention of U.S. policymakers and lawmakers. Among the most important issues are drug production and trafficking, immigration (especially to North America), gang activity and deepening democratization vis-à-vis the rise of populism. Each of these issue areas links up with critical components of U.S. domestic and foreign policy. The intersection of these issues—the potential for emerging threats from powerful states and/or non-state actors operating in the Western Hemisphere to harm U.S. security and economic interests—suggests to some that a more assertive regional policy may be in order. Yet the United States must also tread carefully if it is to enjoy success on these fronts. Terrorism and Regional Security. Five years after the 11 September 2001 terrorist attacks on the U.S. homeland, few issues animate U.S. officials and the American electorate alike as strongly as the Global War on Terrorism (GWOT). Prior to that day, the Bush administration had chosen to focus new attention on Latin America Figure 2: New USARSO (6th Army) organization (particularly on Mexico, but also on other countries in the region). After the attacks, attention shifted to Central 2 new options to act more effectively across the full spectrum of operations. This National Security Watch discusses U.S. Army South (USARSO), responsible for Army forces in Central and South America and the Caribbean, and its transition to and retitling as USARSO (6th Army)