Stalin was just as guilty as Hitler for starting WWII when they both invaded Poland in 1939.
Actually, if we go there, then it is the British and the French who are the guilty ones. Stalin asked them for an alliance, to contain Germany, they turned him down. Then they aided Hitler's rearmement of the Rhineland, annexation of Austria, Sudatenland and then all of Czech. They aided him by doing nothing and allowing no one else to do anything.
"Stalin was just as guilty as Hitler for starting WWII when they both invaded Poland in 1939"
Let's raise the ante - Hitler rose to power only because of the backlash to Stalin's genocide of 10 million in 1933. Many of these were Mennonites living in Ukraine that were able to get word back to their relatives in Germany.
No Stalin means no rise of the Nazi party.