That's true but the Allies fought an actual World War; Europe, Asia, Australia\Oceania, Africa, N America, S America and the oceans and seas throughout the world. Stalin fought the brunt of the war in Russia. He was also allied with the Japanese and actually gave Japan information concerning Allied intelligence. After the Allied victory of Okinawa, Stalin declared war on Japan in August of 1945 and invaded Manchuria. He knew the Allies would invade Japan from the south. He wanted a piece of it and would have invaded from the north. If that happened Japan as we know it today would not exist. It'd been another Germany; there would be North Japan and South Japan; North Tokyo and South Tokyo. It was also estimated that an invasion of Japan would have claimed at least a million lives.
I'm not disparaging the Russian people at all. They suffered the most during the war and a lot of that is on Stalin. To claim Stalin saved Europe is quite laughable.