What was supposed to have happened on Dec. 7, 1941 was a declaration of war by Japan followed by a preemptive attack on Pearl, which was hoped to make America capitulate quickly to cut their losses. Despite the Lend Lease program, most Americans did not want to get dragged into another world war... they had their own problems with recovering from the Great Depression.

We all know what happened instead.

As for Hitler... he was nuts, but had one hell of a cult following. And he had a some impressive military minds to help him carve out his empire... thank god his megalomania made him override their sage advise when he really should have been listening. I think he declared war because he was pissed off by America's aid to England and he too thought that Americans wouldn't have the heart to fight, especially given the large Germanic population within America. Not 15 miles from where I grew up, residents had swastikas painted on their roofs to let German bombers know who not to bomb. So I guess Adolf wasn't the only nut out there.

If I were to postulate an alternate history where America stayed out of the war, I'd say that Japan & Germany would have carved up the Soviet Union between them, England would have been toast, and Canada, the US and Mexico would have been forced into some kind of North American alliance for self protection. imho