A sudden, overwhelming military attack during war is a blitz. Sometimes a major blitz can lead to the end of a conflict.
The idea of a blitz is that it either overpowers or completely surprises the enemy, and it often involves bombing from overheard. The military use of blitz has migrated to sports as well, especially in American football when the defense bursts through the offense or rushes the passer. Any kind of unexpected attack, in fact, has come to be known as a blitz. The word comes from the German Blitzkrieg, "rapid attack."