Stalin was our ally in WWII only because Churchill knew that England could not fight Hitler alone. Those of us who were alive at that time knew that as soon as the war was over, Stalin would turn against us. But we won the damn war against Hitler, didn't we? My enemy's enemy is my friend. Blair has risked his own career to join our President Bush in the war on terror. So I can't put him in the same category as Stalin.
No, Stalin was our semi-ally in World War II because Hitler launched Operation Barbarosa against him and declared war on the US and neither had much choice in the matter.