"Maybe this looks obvious looking back with that 20/20 hindsight, it's even possible that it's true. It's also possible that it's just Monday morning quarterbacking."
That is an absolutely true statement :)
As much as I think I'm right, I cannot deny your point there, and you are right that the divisions tied down in Italy were prevented them from being used to defend against the Normandy invasion. That is the strongest argument I see against my contention, and I appreciate the criticism.
Two other things - when Churchill referred to the 'soft underbelly' of Europe, he was referring to the Balkans. He stated in his history of WWII that he had wanted to invade and retake Greece, that he saw it as a point of honor to stand with them after Britain's failure to prevent the Germans from taking them (after Italy's failure).
Also, after all the atrocities the Germans had committed in their invasion of the USSR, there is no way, absolutely no way that Stalin would ever have allied with him. Stalin had trusted him (stupidest. move. ever!), and now he knew he had been betrayed (and in the eyes of sociopathic authoritarian rulers, betrayal by others is the worst of all sins - remember, he allowed his own son to die in a German POW camp even when they had reached out to propose a swap). At that point, he would never have allied - or even agreed to a cease-fire - with the Nazis.