why warn them ahead of time when you can just get some less stuffty technicians running itwas the cold war directly caused by ww2, though?
Was caused by aggression and will of the West and East to spread their ideologies after World War 2. So no World War 2, no Cold War, no space race. Also warfare would probably be fought just like it was in World War 1 which was static, trenches, large losses of life. Germans invented mechanized warfare, without mechanized warfare, wars would take years instead of a few weeks.
Also Albert Einstein would have stayed in Germany, there would be no Israel, there would be No Schindler's list or Dream Works.