In 1941, the US Army had taken over some of the Disney Studio lot for the war effort and a section of the animation studio was put to work solely on war related propaganda films. In 1942, a book by Alexander Seversky came out called Victory Through Air Power, which explained how the only way to win the war would be with air craft bomber planes. Walt Disney read this book and agreed with what Seversky said, so he quickly made a deal with the author to make a film version to help spread the word. As a result, Victory Through Air Power wasn't made for entertainment purposes, but for education purposes.
Leonard Maltin calls it "The most unusual film that Walt Disney ever made," and that's probably true. The film is in full Technicolor and is about 60% animation, 40% live action. It had little commercial appeal and cost a lot of money, but Walt's hope for the film wasn't money or critical acclaim, it was the hope that government officials would see the film and apply it's teachings to the war effort. The film was released on July 17, 1943. It didn't make money and was bashed by critics, but the film did serve the purpose that Walt had wanted. It was seen by Winston Churchill, who showed it to President Roosevelt. After seeing the film, Roosevelt made a commitment to building bomber planes and using them in the war.
This was the first Disney feature to not be distributed by RKO. They refused to release it because of the lack of commercial appeal, so Walt took it to United Artists. Like Pinocchio and Dumbo, Victory Through Air Power was nominated for an Academy Award for best score. Unlike Pinocchio and Dumbo, it didn't win the Oscar.
Even though the film was made more for education than for entertainment, it isn't completely void of entertainment. The 19-minute opening animated sequence about the history of aviation and the U.S. air force is quite entertaining. The film then introduces Alexander Seversky with his qualifications as a trustworthy source of information. Seversky speaks to us from various parts of his "office," which is actually a set at the Walt Disney Studios. Seversky's talking points are highlighted by animated segments, most of which are very well done, although at times Disney used limited animation to cut the production budget.
Most of what Saversky has to say is no longer relevant, since it was geared at 1943 American audiences, but it is still interesting. To get the most out of this film, you pretty much have to be a history or war buff. Beyond that, it helps to also be an animation fan or a Disney fan or better yet, both. I myself am a Disney and animation fan, but am not so much a history or war buff. I enjoy parts of the film, but overall it is tough to sit through.
Victory Through Air Power has only ever had one home video release, which was through the Walt Disney Treasures DVD line in 2004 as part of the 'On the Front Lines' set, which contains other war-era Disney shorts. It was limited to 250,000 copies, but is still easy to come by.