United States Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution. The oldest and most senior branch of the U.S. military in order of precedence, the modern U.S. Army has its roots in the Continental Army, which was formed 14 June 1775 to fight the American Revolutionary War (1775–1783)—before the United States was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army. The United States Army considers itself to be a continuation of the Continental Army, and thus considers its institutional inception to be the origin of that armed force in 1775.
The U.S. Army is a uniformed service of the United States and is part of the Department of the Army, which is one of the three military departments of the Department of Defense. The U.S. Army is headed by a civilian senior appointed civil servant, the secretary of the Army (SECARMY) and by a chief military officer, the chief of staff of the Army (CSA) who is also a member of the Joint Chiefs of Staff. It is the largest military branch, and in the fiscal year 2020, the projected end strength for the Regular Army (USA) was 480,893 soldiers; the Army National Guard (ARNG) had 336,129 soldiers and the U.S. Army Reserve (USAR) had 188,703 soldiers; the combined-component strength of the U.S. Army was 1,005,725 soldiers. As a branch of the armed forces, the mission of the U.S. Army is "to fight and win our Nation's wars, by providing prompt, sustained land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders". The branch participates in conflicts worldwide and is the major ground-based offensive and defensive force of the United States.
The U.S. Army is made up of three components: the active component, the Regular Army; and two reserve components, the Army National Guard and the Army Reserve. Both reserve components are primarily composed of part-time soldiers who train once a month—known as battle assemblies or unit training assemblies (UTAs)—and conduct two to three weeks of annual training each year. Both the Regular Army and the Army Reserve are organized under Title 10 of the United States Code, while the National Guard is organized under Title 32. While the Army National Guard is organized, trained and equipped as a component of the U.S. Army, when it is not in federal service it is under the command of individual state and territorial governors. However, the District of Columbia National Guard reports to the U.S. president, not the district's mayor, even when not federalized. Any or all of the National Guard can be federalized by presidential order and against the governor's wishes.
The U.S. Army is led by a civilian secretary of the Army, who has the statutory authority to conduct all the affairs of the army under the authority, direction and control of the secretary of defense. The chief of staff of the Army, who is the highest-ranked military officer in the army, serves as the principal military adviser and executive agent for the secretary of the Army, i.e., its service chief; and as a member of the Joint Chiefs of Staff, a body composed of the service chiefs from each of the four military services belonging to the Department of Defense who advise the president of the United States, the secretary of defense and the National Security Council on operational military matters, under the guidance of the chairman and vice chairman of the Joint Chiefs of Staff. In 1986, the Goldwater–Nichols Act mandated that operational control of the services follows a chain of command from the president to the secretary of defense directly to the unified combatant commanders, who have control of all armed forces units in their geographic or function area of responsibility, thus the secretaries of the military departments (and their respective service chiefs underneath them) only have the responsibility to organize, train and equip their service components. The army provides trained forces to the combatant commanders for use as directed by the secretary of defense.
By 2013, the army shifted to six geographical commands that align with the six geographical unified combatant commands (CCMD):
United States Army Central headquartered at Shaw Air Force Base, South Carolina
United States Army North headquartered at Fort Sam Houston, Texas
United States Army South headquartered at Fort Sam Houston, Texas
United States Army Europe headquartered at Clay Kaserne, Wiesbaden, Germany
United States Army Pacific headquartered at Fort Shafter, Hawaii
United States Army Africa headquartered at Vicenza, Italy
The army's most common vehicle is the High Mobility Multipurpose Wheeled Vehicle (HMMWV), commonly called the Humvee, which is capable of serving as a cargo/troop carrier, weapons platform and ambulance, among many other roles. While they operate a wide variety of combat support vehicles, one of the most common types centers on the family of HEMTT vehicles. The M1A2 Abrams is the army's main battle tank, while the M2A3 Bradley is the standard infantry fighting vehicle. Other vehicles include the Stryker, the M113 armored personnel carrier and multiple types of Mine Resistant Ambush Protected (MRAP) vehicles.
While the United States Army Aviation Branch operates a few fixed-wing aircraft, it mainly operates several types of rotary-wing aircraft. These include the AH-64 Apache attack helicopter, the UH-60 Black Hawk utility tactical transport helicopter and the CH-47 Chinook heavy-lift transport helicopter. Restructuring plans call for reduction of 750 aircraft and from 7 to 4 types. The Army is evaluating two fixed-wing aircraft demonstrators; ARES, and Artemis are under evaluation to replace the Guardrail ISR (Intelligence, surveillance and reconnaissance) aircraft. Under the Johnson-McConnell agreement of 1966, the Army agreed to limit its fixed-wing aviation role to administrative mission support (light unarmed aircraft which cannot operate from forward positions). For UAVs, the Army is deploying at least one company of drone MQ-1C Gray Eagles to each Active Army division.
The United States Army employs various weapons to provide light firepower at short ranges. The most common weapon type used by the army is the M4 carbine, a compact variant of the M16 rifle, along with the 7.62×51mm variant of the FN SCAR for Army Rangers. The primary sidearm in the U.S. Army is the 9 mm M9 pistol; the M11 pistol is also used. Both handguns are to be replaced by the M17 through the Modular Handgun System program. Soldiers are also equipped with various hand grenades, such as the M67 fragmentation grenade and M18 smoke grenade.
Many units are supplemented with a variety of specialized weapons, including the M249 SAW (Squad Automatic Weapon), to provide suppressive fire at the squad level. Indirect fire is provided by the M320 grenade launcher. The M1014 Joint Service Combat Shotgun or the Mossberg 590 Shotgun are used for door breaching and close-quarters combat. The M14EBR is used by designated marksmen. Snipers use the M107 Long Range Sniper Rifle, the M2010 Enhanced Sniper Rifle and the M110 Semi-Automatic Sniper Rifle.
The army employs various crew-served weapons to provide heavy firepower at ranges exceeding that of individual weapons.
The M240 is the U.S. Army's standard Medium Machine Gun. The M2 heavy machine gun is generally used as a vehicle-mounted machine gun. In the same way, the 40 mm MK 19 grenade machine gun is mainly used by motorized units.
The U.S. Army uses three types of mortar for indirect fire support when heavier artillery may not be appropriate or available. The smallest of these is the 60 mm M224, normally assigned at the infantry company level. At the next higher echelon, infantry battalions are typically supported by a section of 81 mm M252 mortars. The largest mortar in the army's inventory is the 120 mm M120/M121, usually employed by mechanized units.
Fire support for light infantry units is provided by towed howitzers, including the 105 mm M119A1 and the 155 mm M777.
The U.S. Army utilizes a variety of direct-fire rockets and missiles to provide infantry with an Anti-Armor Capability. The AT4 is an unguided projectile that can destroy armor and bunkers at ranges up to 500 meters. The FIM-92 Stinger is a shoulder-launched, heat seeking anti-aircraft missile. The FGM-148 Javelin and BGM-71 TOW are anti-tank guided missiles.
The U.S. Army's principal artillery weapons are the M109A6 Paladin self-propelled howitzer and the M270 Multiple Launch Rocket System (MLRS), both mounted on tracked platforms and assigned to heavy mechanized units.