We have recent history to demonstrate: WW2 followed by the cold war. Is there a Nazi Germany today? No. Could there be something similar again? Of course.
Hell, there's even a show on Amazon (based on a book) centered around the idea of an alternate history where the Allied forces lost WW2 and the US is occupied territory.
Hell, there's even a show on Amazon (based on a book) centered around the idea of an alternate history where the Allied forces lost WW2 and the US is occupied territory.