Guarda Film Completo Online. On the 16th December 1944 Hitler launched Operation Wacht am Rhein against the largely unsuspecting American component of the Allied Army. Twenty Divisions consisting of 410000 men, 2600 artillery pieces nad 1400 tanks and assault guns attacked the American 1st Army on a 110 kilometre front. How had this happened ? This film examines why the Allies were not prepared.