I'm way out of my league when it comes to 20th century history, but if the UK and France lost WWI (maybe because the US remained neutral), then you might see fascist movements spring up in London and Paris like in TL-191. Russia is taken over by the Communists, Franco takes over Spain, and Mussolini takes over Italy, as in OTL. Strangely, at that point, Germany might be the only sane major power in Europe. Perhaps due to the animosity between the Germans and the Anglo-French, you might see Berlin leaning toward Communism and cozying up to the USSR for extra protection. I'm unsure that even an Austria-Hungary which was victorious in WWI could keep from falling apart, but I think it would follow Germany in allying with the Soviets. Thus:
Fascist Powers: UK, France, Spain, Italy
Communist Powers: Germany, Austria-Hungary, USSR
So there you have it. WWII commences for obvious ideological reasons, and Europe is once again drowned in blood. An interesting question might be how the other major powers in the world (US, Japan, China) would align if they became involved in the conflict. China may end up embroiled in a civil war between Communists and fascists. While Japan isn't exactly friendly with the USSR, if they decided to pick a side they might ally with the Communists (even if their government was fascist) if only to grab all those juicy colonies in south and southeast Asia belonging to the Fascist Powers. If I were POTUS then, I'd keep the US the hell out of the war. But if they decide to go in, I'd guess they'd side with the fascists, not just because Communism is unpopular in the US, but also to avoid siding with the Japanese. Whichever side the US throws its lot in with will probably win. But again, I'm just talking out of my ass here. It'd make for an interesting TL anyway.