France would have to lose at least Alsace and Lorraine, no way Hitler was giving that back.
What about the West's treaties with Poland which they basically ignored anyway when Poland was invaded? What about all of the Jews from Germany to Moscow and beyond?
Those are just minor details to the crowd that thinks the USA could have gotten away with staying out of the war while those two powers duked it out. Remember Woodrow Wilson’s re-election campaign slogan (and famous last words), “He Kept Us Out Of War” . . . and once a tyrant claims the crown jewels of Charlemagne for himself as Adolf did, he ain’t going to stop at anything.