"... Stalin never really wanted to go to war with Germany ..."
I simply do NOT believe that. Stalin had been itching ... Soviet Communism had been itching .. to take on Fascism since the mid thirties .... Spain, for starters.
Starting in the street fights in Berlin circa 1918-19, the Fascists and Communists couldn't keep their hands off each other
, they wanted "at it".
As for this comment ".... Hitler saw that and it helped him realize how weak Russia was at the time". Hitler knew Russia wasn't weak ... he saw what Zhukov did to the Japanese in Khulgin Gol in the summer of 1939 ... (just months
before Finland, the Soviets had thoroughly whipped a German ally - Japan).
The bottom line - if Hitler hadn't been mad, he would have stopped at Dunkirk - with perhaps a few aerial thrusts to let the British public know what was in store for them - and begun negotiations. There would have been a measurable public outcry in Britain for "peace" - in lieu of a war for France (the second in 30 years.)
Hitler's mistake was that misread situations because he was (1) paranoid, (2) egotistical, and (3) mad. He was further ahead at the fall of Dunkirk than he was again -- but he didn't realize that.
MM