here's a (kinda farfetched) POD that might help with the scenario... let's suppose that Churchill decides not to send all those troops to Greece, and the Brits complete their conquest of Italian N. Africa, and Hitler declines to send his own forces to help out a lost cause... and the Americans still enter the war after Pearl Harbor... but this time, they have a different strategic situation in the Med, with the Italians and Germans out of N. Africa... might they decide to invade Sardinia and Corsica sometime in late 1942? Granted it's a huge stretch, and they would likely decide to take over French N. Africa first, but it gets the job done...