America was unified in WWII for one reason only: the American Left wanted to save Stalin. The Left was for war with Germany from June 22, 1941. Pearl Harbor on December 7th allowed the Left to go after Germany and resupply Stalin. The war with Japan was just incidental to the Left.
As it turned out, the Left shot their own foot. With Lend-Lease to Stalin, Russia was able to defeat Germany all by itself and Normandy only prevented Stalin from taking all of Europe.
Nonsense.
You take away the air war against Germany and you free up a whole bunch of troops and guns to be used on the Eastern Front....not to mention the impact on German manufacturing.
If we don't invade North Africa and Italy all those resources could have been used against the Soviets.