I actually know a bit about WWII. My dad is very much into history and I had the opportunity to learn a lot from him when I was growing up.
Last time I checked, the US and Stalin were allies against Germany during the war. Without the support of the Soviet offensive, the US and the other European allies would not have been able to fight effectively and most probably would have lost (Hitler was making a huge mistake with Operation Barbarossa, it drew a vast chunk of his resources away from the western front to attack someone he had agreed to leave alone, and in the end he could not hold the territory captured - and also lost those resources in the Russian counter-offensive).
If I remember correctly, the Soviet advances in Finland were stymied by the Finns themselves, and had nothing to do with the US.
After the war, the question was what to do with Germany and the countries occupied by the Nazis. As far as I'm aware, the decision was that those to the east would be occupied and held by the Soviets, and those to the west would be held by the Allies - most of whom were holding their own country. Germany was split, as was Berlin. This was done to keep the peace in the aftermath of the war, and I very much doubt that the Allies had the resources to do alone. They were then left in a sticky situation because of the clash of two different ideologies, and so the Iron Curtain came down to keep them separated.
You're suggesting that in this scenario, without the deterrent of the US, Stalin would have decided to start another war that his country probably couldn't support, to invade territories already shattered by the Nazis (thereby having very little resources to offer) and full of French and British troops.
You're suggesting that he could then have held these territories, despite how far and how thinly his armies would have been spread across the length of Europe, considering they would have taken severe losses to capture said territories, and also considering that the native population of said territories already have a history of very strong resistance to foreign occupiers (French Resistance anyone?).
This is assuming he wouldn't even try to capture Britain, seeing as that would have been unimagineably expensive and the Nazis already tried and failed.
I've read enough of history to know that the US, and every other country for that matter, has only acted in its own self-interest, whether the results of those acts were good or bad. In the opposite scenario, the US had absolutely no reason to try and make an empire out of Europe for the same reasons - it would be massively expensive, there was no real economic benefit, and they would face strong resistance from the natives who wanted their countries to be free. Added to that, I have no idea how the US government would convince their own citizens that it would be a good idea.
My point is in the absence of the US, it's hard to say what the USSR would or wouldn't have done - but trying to invade the rest of Europe would have been a foolish course of action, and one that most likely couldn't have succeeded.
So please, dispense with the arrogance Randman - the US is not some great guardian angel defending us poor weak Europeans from the satan that is communism. There were European troops in the war too that fought like lions - for example the RAF pilots in the Battle of Britain - and to suggest that they would just lie down and let the Soviets take over is more insulting than I can possibly convey.
"Those who fear the darkness have never seen what the light can do."
™ Version 4.2
