Almost finished with a book on the 1919 Paris talks, and it's brought up a wide range of AH possibilities. One of the most prominent revolves around the question "What if Italy hadn't entered WWI?" More specifically, what if the Allies hadn't succeeded in (or decided against) coaxing Italy to join the Entente through the 1915 Treaty of London, and so Italy remained neutral for the duration of the war? Without Italian participation, would the war have lasted longer (though still ending with Allied victory), or ended with Germany and Austria-Hungary still intact or at least less weakened than in OTL? Without the losses and "mutilated victory" legend that came about from Italian participation in the war, would Fascism have arisen in 1922, and provided a template for the Nazis and other authoritarian regimes in the 1920s and 1930s?