Do you think Nazi Germanys invasion of the USSR was the number one reason why it lost in World War II?
As Churchill wrote in “The Hinge of Fate,” the Allies were confident of ultimate victory because Germany had been unable to stand against an encircling alliance for the previous 300 years–but there was a mistake BEFORE the mistake, and that was the absolutely stupid decision between Hitler and Air Marshal Goering that they were losing too many planes attacking British radar so they stopped doing it. (The radar installations were the most ferociously defended targets in Britain.) By not killing the radar, they lost the Battle of Britain; and thus left an enemy in their rear. This enemy became an unsinkable aircraft carrier for the United States when the Germans turned to the Soviet Union and the Allies prepared for D-Day. I haven’t read this anywhere as a motive for his attacking the USSR, but I live in Ukraine, and a friend of mine’s father had been a tank commander in WWII and said that Stalin was planning to attack Hitler.