First, forgive me for running another WWII thread.
That said, I've noticed a lot of good criticism here regarding alternative Mediterranean theater options for the Allies as things stood upon American entry into the war, even if the necessity for the Italian campaign is acknowledged.
Southern France being too tough a nut to crack, and the Balkans being a slow slog to nowhere fast, Italy seems the most logical target in hopes of quickly knocking out a major Axis power and establishing a presence on the Continent. But aside from Sicily, Italy was a slow, grinding struggle from one line of defense to another.
What would it take for the Allies instead to be at least at the Po river by the time the Normandy landings were ready? And what could they do from there? Fighting through the Italian and Austrian alps would be pretty brutal, and German resistance there likely would be both fanatical and effective, given the terrain. Might there be greater Allied activity in Yugoslavia from there?
As for the how, I suppose one might replace Kesselring with someone incompetent for a start, and have Husky include landings in Italy proper to prevent effective Axis evacuation of Sicily.
What would be the effects of such a campaign in Italy itself? Does Mussolini get hung from a lamp post early, or flee to Germany to be tried at the end of the war? Presumably, a more expedient Allied advance prevents or limits the Axis benefit of establishing the Italian Social Republic in the north, in addition to denying the use of Italian industry.
Would a more impressive Allied campaign in Italy have any effect on Allied plans for Overlord and Dragoon, by drawing away German resources to the Alps, or by increasing the demands on Allied material?
Most importantly, is this sort of success a reasonable possibility, or are German advantages too significant to be that easily overcome south of the Po?