The Allies were the good side. No debate. Soviets were bad, but the Soviets were never truly on the Allies side.
If Hitler hadn't broken the Non-Aggression Pact and continued to focus on the Western Front, I think they would've eventually joined the Axis powers. And even if he still waged war against them, if the Soviet Union was powerful enough at the time to destroy Germany on its own, it would have never sought such alliances. They only cared about themselves.
Had the Russian atomic bomb been ready to go in 1941, I have no doubt in my mind Stalin would've flattened Berlin and the German countryside and called it a day. The future of France, Poland, Italy, and the Japanese Empire was of no concern to him.
Huh? Why would Stalin would stop there rather than march right on to the Atlantic.
Stalin was reactionary. I know it seems obvious that he would he want to conquer the world, but he was a very unpredictable man. And when it came to actual unprovoked aggression, relatively slow in his tactfulness (compared to, say, Khrushchev). And as mentioned earlier in the thread, nobody was prepared to fight another war immediately after ending WWII.
I think he would've destroyed Germany, basked in the victory, taken great pride in the rest of the world fearing him, and waited way too long to press on. Thus, allowing the Manhattan Project to be completed and the US to catch up. And the Cold War would begin anyway, but not because of the USSR stepping up and challenging the US's new found dominance. Instead, it would be the US challenging the Russians.