The Rack (1956)

Director: Arnold Laven
Cast: Anne Francis, Cloris Leachman, Edmond O'Brien, Lee Marvin, Paul Newman, Robert Burton, Walter Pidgeon, Wendell Corey

Synopsis:

Army Captain Edward Hall returns to the US after two years in a prison camp in the Korean War. In the camp he was brainwashed and helped the Chinese convince the other prisoners that they were fighting an unjust war. When he comes back he is charged for collaboration with the enemy. Where does loyalty end in a prison camp, when the camp is a living hell?