(Photo from ComicBookResources.com)
Despite his recent declaration that he is no longer an American citizen but a citizen of the world (not sure if that carried over to the New 52), Superman is right up there with Captain America as a representative of the Red, White & Blue. Prior to American involvement in World War II, Supe's creators worked up a comic showing how the Man of Tomorrow would end the war, which ended up being Superman capturing Adolf Hitler and Joseph Stalin single-handedly and taking them to Geneva to stand trial.
While that bit of history is indisputable, there has been some question over the years as to whether or not the Nazis actually provide an official response. Thanks to our friends at ComicBookResources.com, we know they did. Here's all the saga including the Nazis' anti-semitic comeback.