I could see large scale war between Soviets/China vs Japan/Germany though. Now THAT would have been a nightmare on a good day. All countries involved were straight savage in warfare on a good day. Something for the history books to say the least. We also would have developed a nuke in our isolation.
At the end of the day, it would see be America vs the Totalitarians. Soviets, Nazis....still same old cold war. I'm just wondering where GB would have ended up. We would have been drawn in no matter what, but to what point and end. Would the V2s have stopped?
Who the hell knows.