In the two wars since World War II, (Korea and Vietnam) the Air Force
wanted to maintain a close support aircraft that could also counter the
odds with the on-growing Russian Tank forces near the West Germany's boarders.
With the collapse of the USSR the A-10 was thought not to be needed for
the active service, and was to be slotted for the reserves. Such thinking
has changed, the A-10 proved it's importance as a close support aircraft
in Desert Storm.