Robert Ryan and Richard Brooks, the author of the novel 'The Brick Foxhole' which this film was based on, both served in the U.S. Marine Corps during WW II. Ryan asked Brooks if his book ever was accepted by Hollywood to consider him for the unsympathetic role of Montgomery. But another version of this story maintains that Ryan met Brooks in the library of Camp Pendleton, told him he was an actor who was determined to play the movie role of the villain, especially because, he insisted, 'I know that son of a bitch. No one knows him better than I do'. Two years later, outside the theater where Crossfire (1947) had just previewed, actor Ryan--who had indeed played the role he had once sought--asked writer Brooks, 'What do you think?'
Despite receiving an Academy Award nomination, Robert Ryan rarely talked about his breakthrough role, because he wasn't too happy about the negative aspects of his character, who was a murderous, anti-Semitic psychopath. In real life, Ryan was a committed liberal progressive who detested any forms of bigotry.
It has been suggested that one reason the film failed to win any Oscars was due to director Edward Dmytryk and producer Adrian Scott's refusal to testify before the House Un-American Activities Committee (HUAC). Even more, Dmytryk--a Canadian who had become an American citizen only a decade earlier--was one of the notorious anti-HUAC 'Hollywood Ten.' Indeed, subsequent to the HUAC hearings, both Dmytryk and Scott were blacklisted for political reasons and unable to work in Hollywood.