Why We Fight Vol. 1-5 (c. 1940) DVD
 
Why We Fight is a series of propaganda films produced by the US Department of War from 1942 to 1945, during World War II. It was originally written for American soldiers to help them understand why the United States was involved in the war, but US President Franklin Roosevelt ordered distribution for public viewing.
 
Academy Award-winning filmmaker Frank Capra, daunted but impressed and challenged by Leni Riefenstahl's 1935 propaganda film Triumph of the Will, worked in direct response. The series faced various challenges, such as convincing a noninterventionist nation to get involved in the war and to become an ally of the Soviet Union. Many entries feature Axis powers' propaganda footage from up to 20 years earlier, recontextualized to promote the Allies.
 
Although primarily edited by William Hornbeck, some parts were re-enacted "under War Department supervision" if no relevant footage was available. Animated segments were produced by Walt Disney Productions, and the animated maps followed a convention of depicting Axis-occupied territory in black.