Air Force, the air arm of a nation's military forces, usually separately organized as coequal with the army and the navy. The striking power of an air force is based on airplanes and missiles. Armies and navies may also employ airplanes and missiles for specific purposes. An air force comprises of pilots and other personnel, aircraft, support equipment, and military bases. Some air forces possess guided missiles and spacecrafts as well.

Air forces have four principal missions: