Stalin clearly wanted the U.S. in the war.
Stalin did not trust anyone. He was given timely intelligence, several times during the war, that he could have used to great advantage. He was not told how it had been obtained, or that the Brits, with the help of the Poles, had cracked the German Army codes. He ignored them all.
There’s some interesting history, there:
Early in the war a very real fear Stalin had was that the Japanese would attack him in the east, putting him in a two front war. Stalin needed all available troops for fighting at Stalingrad and Kursk, obviously.
One of Stalin’s most effective spies was Richard Sorge, who was dispatched to Japan to ferret out the question of Japanese intentions against Stalin. After much digging and risk Sorge informed Moscow (from a radio on a beach, as the Japanese Gestapo equivalent closed in on him) that Stalin needn’t worry about any eastern front —the Japanese were very busy elsewhere:
Only by being armed with this precious info could Stalin feel free to shift west the yuge legions of troops up until then tied down in a needless eastern guarding action (this had major implications at Stalingrad and elsewhere).
But before all that in fact Sorge many times plainly told Stalin the exact date of Barbarrossa’s opening day. And later when Hitler postponed Barbarossa Sorge told Stalin that, too.
Yet true to his paranoid nature Stalin disbelieved and did nothing.
He also did NOTHING to save Sorge, who went to the noose never losing faith Stalin would save his neck.
Oh, and Stalin did nothing to save his own son, taken POW by the Wehrmacht.
What an insect.