What if the Nazis had won?
The science fiction subgenre that answers questions like that is called "Alternate History." Phillip K. Dick's 1962 Hugo-winning novel (Yes, youngsters, they made a book out of the TV show) is the classic, but hardly the only, example.
1957, my short story which will appear in the forthcoming noire fiction anthology edited by Larry Correia and Kacey Ezell (working title No game for Knights), is my take on the question. Well, actually, it's a small part of my take. The rest will form one or more novels.