A: A wave of patriotism swept the nation during World War II, and Walt Disney was one of many caught up in it. He vowed to do what he could to help the war effort, spearheading the production of training and propaganda films by his studio and the designing of military insignia for fighting units. By the 1940s, Donald Duck had become the most popular character at the Disney Studio, and since he had an explosive temperament, he seemed a natural for war-related cartoons.