Hitler wanted the Oil of Caucasus, and the huge Sowiet Union to settle, and he had a deep hate towards Slavic Peoples / East Europeans, which he wanted to enslave.
Stalin expected a german Attack, it was clear for him Hitler is an extreme Warmonger. Stalin wanted to win time to modernize the Sowiet economy and military, and he expected a German attack after an Invasion of Great Britain, he said "Hitler is not that stupid to risk a 2 front War" Stalin needed also time to cleanse the Sowiet Forces of opponents.
That's the same thing Barack Obama has been doing with the U.S. military. But I digress. American history as it was taught since 1941 and still today don't mention that when Germany invaded Poland in 1939 from the west, two weeks later the Soviet Union invaded Poland from the east. Also Germany's main source for military intelligence on what was happening in England from 1939 to 1941 was the Soviet Union. Also the CPUSA rook it's orders from the Kremlin and the CPUSA controlled many of the labor unions in America at the time and conducted wild cat strikes at war plants and on the docks all across America in 1941 to prevent war materials from reaching England during the "Battle for Britain." Stalin's agenda was to keep the war between Germany and England to go on as long as possible, hoping that Germany would invade the UK and that the German military would be weaken, over stretched and worn out. That the Soviet / Russian archives that have been released since the end of the Cold War, Stalin was planning on attacking Germany as soon as his military was capable of waging the war against Germany. Stalin and Hitler were both socialist. But Hitler despised communist and Slavs and Stalin believed that communism was the true form socialism, not Nazism. Both Hitler and Stalin were anti capitalism. They both has a common enemy.
