The Battle for Castle Itter, World War II military engagement in which U.S. soldiers joined forces with renegade German troops to turn back a Waffen-SS assault on a stronghold in Tirol, Austria, where elite French political figures were being held prisoner by the Nazis. The battle took place on May 5, 1945, three days before the official end of the war in Europe. It is thought to be the only time that Americans and Germans fought as allies during World War II. Hanna: American! Are you ok!?