Prelude to War is the first film of Frank Capra's Why We Fight film series commissioned by the Office of War Information (OWI) and George C. Marshall. It was made to educate American troops of the necessity of combating the Axis powers during World War II based on the idea that those in the service would fight more willingly and ably if they knew the background and the reason for their participation in the war. The film was later released to the general American public as a rallying cry for support of the war.