Assuming the nazis never come to power, and thus WWII avoided then what are the political, cultural, economic, and military trends of the 1940s, 50s, & 60s?
My first thought is the US does not recover nearly as fast to its pre Depression economic levels & remains some distance from its dominating position of the second half of the 20th Century.
My second is the European colonial powers are in a better position to retain their empires through the 20th Century.