Voyska PVO (Russian: Войска ПВО, or PVO Strany until 1981) was the air defense branch of the Soviet military. PVO is short for Protivo-Vozdushnaya Oborona or "Anti-Air Defense." Unlike Western air defense forces, PVO Strany was a branch of the military unto itself, separate from the Soviet Air Force. In the 1981 reorganization, Voyska PVO was stripped of many command and control and training assets, which were given to the Air Force. In 1998, it was merged with the Russian Air Force. Its principal role was to intercept U.S. Strategic Air Command bombers as they penetrated Soviet airspace.
The Troops of National Air Defense (PVO) became a separate armed service in 1948 and were given the mission of defending the Soviet industrial, military, and administrative centers and the armed forces against strategic bombing.
PVOStrany was reorganized in 1981 and its name was changed to Voyska PVO (Air Defence Troops), but it maintained its status as an independent branch, and the main body of army air defence troops, including the military schools, were annexed to it.
The Voyska PVO lost its separate command and control system in the reorganization and about half of the fighters and the majority of the flying training system was transferred to the Air Force.