United States Air Force

The United States Air Force (USAF) is the air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its origins to 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established by transfer of personnel from the Army Air Forces with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in order of precedence. The United States Air Force articulates its core missions as air supremacy, global integrated intelligence, surveillance and reconnaissance, rapid global mobility, global strike, and command and control.

The Department of the Air Force, which serves as the USAF's headquarters and executive department is one of the three military departments of the Department of Defense. The Department of the Air Force is headed by the civilian secretary of the Air Force, who reports to the secretary of defense and is appointed by the president with Senate confirmation. The highest-ranking military officer in the Air Force is the chief of staff of the Air Force, who exercises supervision over Air Force units and serves as one of the Joint Chiefs of Staff. As directed by the secretary of defense and secretary of the Air Force, certain Air Force components are assigned to unified combatant commands. Combatant commanders are delegated operational authority of the forces assigned to them, while the secretary of the Air Force and the chief of staff of the Air Force retain administrative authority over their members.

Along with conducting independent air operations, the United States Air Force provides air support for land and naval forces and aids in the recovery of troops in the field. As of 2020, the service operates approximately 5,500 military aircraft and approximately 400 ICBMs. The world's largest air force, it has a $179.7 billion budget and is the second largest service branch of the U.S. Department of Defense, with 321,848 active duty airmen, 147,879 civilian personnel, 68,927 reserve airmen, 105,104 Air National Guard airmen, and approximately 65,000 Civil Air Patrol auxiliaries.