The armed forces of the United States of America in 2002 numbered 1.41 million on active duty and 1.24 million in the Ready Reserve, a category of participation that allows regular training with pay and extended active duty periods for training. The Standby and Retired Reserve includes about 23,400 experienced officers and NCOs who can be recalled in a national emergency. Membership in all of these forces is voluntary and has been since 1973 when conscription expired as the Vietnam war was winding down. The active duty force includes 196,100 women, who serve in all grades and all occupational specialties except direct ground combat units and some aviation billets.
In the 1990s, the armed forces reduced their personnel numbers and force structure because of the diminished threat of a nuclear war with the former Soviet Union or a major conflict in central Europe. Despite the interlude of the Gulf War, 1990–91, the force reductions continued throughout the decade, forcing some restructuring of the active duty forces, with emphasis on rapid deployment to deter or fight major regional conflicts much like the Gulf War, in Korea, elsewhere in the Middle East, or Latin America (e.g. Cuba). The conventional force debate centered on whether the United States could or should maintain forces to fight two regional conflicts simultaneously. In the spring of 1999, the United States took part in the NATO air campaign in response to the crisis in Kosovo, and the ensuing US participation in peacekeeping operations in the region brought with it the prospect of another long-term overseas deployment.
For the purposes of administration, personnel management, logistics, and training, the traditional four military services in the Department of Defense remain central to strategic planning. The US Army numbers 485,500 (71,400 women) soldiers on active duty, divided roughly between 6 heavy (armored or mechanized) divisions, 4 light (infantry airborne, airmobile) divisions, and three independent infantry battalions as well as three armored cavalry regiments, five aviation brigades, and 11 air defense battalions. Army special operations missions go to Special Forces groups, an airborne ranger regiment, an aviation group, and a psychological warfare group with civil affairs and communications support units. The Army has 7,620 main battle tanks, 6,710 infantry fighting vehicles, 15,910 other tracked vehicles, almost 6,000 towed or self-propelled artillery, some 249 aircraft, and about 4,813 armed and transport helicopters. The Army National Guard (355,900) emphasizes the preparation of combat units up to division size for major regional conflicts while the Army Reserve (358,100) prepares individuals to fill active units or provide combat support or service support/technical/medical units upon mobilization. In addition, the National Guard retains a residual state role in suppressing civil disturbances and providing disaster relief.
The US Navy (385,400; 57,800 women) has shifted from its role in nuclear strategic deterrence and control of sea routes to Europe and Asia to the projection of naval power from the sea. Naval task forces normally combine three combat elements: air, surface, and subsurface. The Navy mans 24 nuclear-powered attack submarines with one configured for special operations; most of these boats can launch cruise missiles at land targets.
Naval aviation is centered on 12 carriers (9 nuclear-powered) and 11 carrier aircraft wings. Including its armed ASW helicopters and armed long-range ASW patrol aircraft—as well as a large fleet of communications and support aircraft—the Navy controls 1,510 aircraft and 506 armed helicopters. Naval aviation reserves provide additional wings for carrier deployment. The surface force includes 27 cruisers (22 with advanced anti-air suites), 54 destroyers, 37 frigates, 42 amphibious ships, 27 mine warfare ships, and 21 patrol and coastal combatants. More ships are kept in ready reserve or are manned by surface line reserve units. The fleet support force also includes specialized ships for global logistics that are not base-dependent.
The Marine Corps, a separate naval service, is organized into three active divisions and three aircraft wings of the Fleet Marine Force, which also include 3 Force Service Support groups. The Marine Corps (173,400; 10,500 women) emphasizes amphibious landings but trains for a wide-range of contingency employments. The marines have 403 main battle tanks, 1,321 amphibious armored vehicles, and about 1,000 towed artillery pieces.
The US Air Force (369,700; 56,400 women) has focused on becoming rapidly deployable rather than US-based. Almost all its aircraft are now dedicated to nonstrategic roles in support of forward deployed ground and naval forces. The Air Force stresses the missions of air superiority and interdiction with complementary operations in electronic warfare and reconnaissance, but it also includes 28 transport squadrons. Air Force personnel manage the US radar and satellite early-warning and intelligence effort. The Air Force Reserve and Air National Guard (roughly 183,100 active reserves) provides a wide range of flying and support units, and its flying squadrons have demonstrated exceptional readiness and combat skills on contingency missions. Air Force reserves, for example, provide the backbone of the air refueling and transport fleets.
The armed forces are deployed in functional unified or specified commands for actual missions. The Strategic Command controls the strategic nuclear deterrence forces: 550 ICMBs, 18 Navy fleet ballistic missile submarines, and 178 operational long-range bombers. These forces have undergone reduction to conform with the START arms limitation treaty of 1991, as amended in 1992, so that by the year 2003 the United States will have only 500 ICMBs, 1,728 SLBMs, and 95 nuclear-armed bombers. Strategic Command is complemented by Space Command/North American Air Defense Command. In 2002 the Treaty of Moscow was signed between the United States and Russia to reduce deployed nuclear weapons by two-thirds by the year 2012. As of 2002, the United States had more than 10,000 operational nuclear warheads.
The conventional forces are assigned to a mix of geographic and functional commands: Atlantic Command, European Command, Central Command, Southern Command, and Pacific Command, as well as Transportation Command and Special Operations Command. The Army also maintains a Forces Command for ground forces in strategic reserve in the United States. Major operational units are deployed to Germany, Korea, and Japan as part of collective security alliances. About one-third of active duty personnel are assigned to overseas billets (1–3 years) or serve in air, naval, and ground units that serve short tours on a rotational basis. Peacekeeping forces are stationed in Bosnia, East Timor, Ethiopia/Eritrea, Georgia, Hungary, Iraq/Kuwait, the Middle East, Tajikstan, Turkey, Uzbekistan, and Yugoslavia. Approximately 7,200 US troops are stationed in Afghanistan with Operation enduring Freedom.
Patterns of defense spending reflect the movement away from Cold War assumptions and confrontation with the former Soviet Union and the People's Republic of China. During the 1980s when defense spending hovered around $300 billion a year and increased roughly 30% over the decade, defense spending absorbed roughly 6% of the gross domestic spending, 25% of federal spending, and 16% of net public spending. In the early 1990s, when the defense budget slipped back to the $250–$260 billion level, the respective percentages were 4.5, 18, and 11, the lowest levels of support for defense since the Korean War (1950). In 1999, the defense budget was $276.7 million or 3.2% of GDP. US military assistance abroad shows similar trends. From 1981 to 1991 the United States sold $118 billion in arms abroad and provided some outright grants, military training, and other support services, most in dollar value to its NATOs allies, Sau'di Arabia, Israel, South Korea, and Japan. This spending also declined in the 1990s.