With Lenin and Stalin ruling the USSR and the Prussians ruling the rest of Europe, there is no reason to think that the rest of the 20th Century would be any less violent. Germany and the USSR still would have inevitably gone to war. Modern weaponry, including nuclear weapons and ICBM's still would have been developed.
Assuming there would still have been a USSR. Germany helped get Lenin into Russia to foment revolution, it likely would not have been necessary without the US entry into the war.