Some nifty cultural dissonance there, Donald Duck giving the Nazi salute to a framed picture of Hitler on his bedroom wall. Lyrics to the film's title song (which won a freaking Oscar!):
Nazi: Ist we not der super men?
Hirohito: Aryan pure super men?
Soldier: Ja, we ist der super men!
Röhm: [Prissy voice] Super-duper super men!
Nazi: Ist dis Nazi Land so good? Would you leave it if you could?
Singers: Ja, dis Nazi Land ist good!
Moussolini: We would leave if we could.
Röhm: We bring the world's new order.
Hirohito: [waves small Japanese flag] Heil Hitler's New World Order.
This is the same song that the POWs are performing for their musical in the Movie Harts War. At the time the cartoon was made Americans did not yet know about the Holocaust, they may not have been so goofy with the Aryan Supermen bit if they had.
Alderney was occuplied by the Germans as part of Hitler's Atlantic Wall - there was a concentration camp less than a kilometer from my house - and the island is surrounded by concrete fortifications built by Russian slave labor. When they died or could no longer work, they were thrown into the wet concrete. A lot of truly horrible things happened here. Nobody is known to have escaped.
To see the Nazi ideology as a subject for childrens cartoons, and dealt with in such a whimsical way is a bit of a trip, and makes a bizarre sort of sense given US WW2 propganda. History as it was described at the time.
Animating for Disney in the 40s and 50s must have been one of the most kickass jobs of the era. 'What'd you do at work today honey?', 'Oh, I was drawing pictures of a duck throwing tomatoes at Hitler.' 'That's nice dear.'