In terms of war propaganda cartoons, Der Fuehrer's Face is pretty tame. I mean, we all remember the lashing that Saddam Hussein got from the creators of South Park a decade or so ago. Donald Duck's journey through Nazism is actually kind of cute. And that song at the beginning is pretty catchy, too. Makes you think maybe them Nazis weren't all that bad. Okay, so the cartoon's caricatures of Japanese and German folks is a tad racist. But they get an absolutely FABULOUS dance number which, yeah, is pretty homophobic, but at least it showed that the Nazis weren't above having a good time. And who doesn't like having fun? Fucking Communists is who. But we had to leave them out of this cartoon because they were sort of our allies at that point.
I don't think it's exactly a spoiler to say that by the end of the story, Donald Duck wakes up to find out that the whole thing was just a terrible nightmare. He's still in the good 'ol U.S. of A! He loves America! Freedom is awesome! Alas, this final part of the cartoon feels as though it was added as a sort of footnote.