I didn't imply that the russians turned on hitler. I'm quite aware of that part of history. I was implying that the russians turned on the US and its allies when stalin decided he wanted to carve up europe.
I know what you were implying but it is not an accurate understanding of the situation at the end of WWII. Stalin had DRIVEN Hitler out of Eastern Europe (traditionally part of the Russian sphere of influence) and had MILLIONS of soldiers there. There was NOTHING we could have done to change that. Stalin never attacked US forces so he didn't really "turn" on us any more than we "turned" on him once it became clear that we had different strategic intentions and needs.
It is sheer nonsense to claim that the geopolitical realities in Eastern Europe could have been changed by anything other than a massive military attack. An attack of which we were not capable at the time. Nor was anyone "sold out" by FDR.
In addition, after the fall of Hitler we had hopes Stalin would help against Japan which was still unconquered.