According to Kenneth Goff in Hitler Hoax, the reason Stalin had Trotsky whacked was because he feared a nαzι-Trotsky partnership. The author claims Hitler was a Rothschild and that Catholic Austrian PM Dollfuss was killed because he knew and was going to blow the whistle.
I have also learned recently that Rhienhard Gehlen(the supposed 'Paper Clip' nαzι) was actually(like Hitler and Mussolini) a Communist double agent.
He fed bogus info to the German high command that set up the Stalingrad disaster.