Walt Disney put huge amounts of money into WWII propaganda films. There is a DVD set of all the WWII shorts available, Walt Disney Treasures - On the Front Lines (1943) which is really entertaining to watch.
Save the Kitchen Fat!!
Walt Disney was too young to serve in WW-I. He did serve as an ambulance driver in France at age 16, by lying about his age. He was very patriotic, rumors to the contary notwithstanding. http://www.snopes.com/disney/waltdisn/discharg.htm