blitzkrieg

blitzkrieg - n - A swift, sudden military offensive, usually by combined air and mobile land forces.

Literally, "lightning war." Another German word that has entered the English-speakers vocabulary.

It wasn't known in 1939, but Germany threw virtually everything it had into its Polish invasion, which began September 1, 1939. Had Germany been attacked from the west at that time, the war in Europe may not have gone any further.