Decision Before Dawn is a 1951 American war film directed by Anatole Litvak, starring Richard Basehart, Oskar Werner, and Hans Christian Blech. It tells the story of the American Army using potentially unreliable German prisoners of war to gather intelligence in the closing days of World War II. The film was adapted by Jack Rollens (uncredited) and Peter Viertel from the novel Call It Treason by George Howe. It was nominated for Academy Awards for Best Film Editing and Best Picture.
By late 1944, it is obvious that the Germans will lose the war. Colonel Devlin (Gary Merrill) leads a military intelligence unit that recruits German prisoners of war to spy on their former comrades.
"Tiger" (Hans Christian Blech), a cynical older thief and ex-circus worker, is willing to work for whichever side is winning. On the other hand, "Happy" (Oskar Werner) is a young idealist who volunteers after his friend is killed by fanatical fellow prisoners for voicing doubts about the war's outcome. Monique (Dominique Blanchar) trains Happy and the others in espionage techniques; she takes a liking to the young man, despite her hatred for Germans.
One day, Devlin receives word that a German general is willing to negotiate the surrender of his entire corps. Naturally, this is given top priority; because of the importance of the mission, an American officer has to go along. Devlin selects Lieutenant Rennick (Richard Basehart), a newcomer who distrusts the German turncoats. Tiger is chosen because he is the only one who knows the area, but he is under suspicion after returning from his last mission without his teammate. Happy is assigned the related task of locating the 11th Panzer Corps, which might oppose the wholesale defection. They parachute out of the same plane, then split up.
In the course of his search, Happy encounters Germans with differing attitudes towards the war, some resigned, like Hilde (Hildegard Knef), a few still defiant, such as Waffen SS courier Scholtz (Wilfred Seyferth). Happy accomplishes his mission by a stroke of luck. Posing as a medic returning to his unit, he is commandeered to treat Oberst von Ecker (O.E. Hasse), the commander of the 11th Panzer.
Afterwards, he is sought by the Gestapo. Narrowly escaping capture, Happy makes his way to a safe house where the other two agents are hiding out. Meanwhile, Tiger and Rennick have learned that the general they were to contact was supposedly injured, but the hospital where he has been taken is under SS guard; without him, the other German officers cannot and will not act.
The radio is knocked out, so they are forced to try to swim across a heavily-defended river to get to the American lines with the vital information. At the last moment, Tiger loses his nerve and runs away, forcing Rennick to shoot him. He and Happy then swim to an island in the middle of the river. When they start for the other shore, they are spotted by the German defenders. Happy creates a diversion, is captured and executed as a deserter, but his sacrifice enables the lieutenant to make it to safety, with a changed attitude about some Germans.