The question of how the USSR could have been defeated at all must be raised as well. What would Moscow have gained the Germans? The Soviet capital, a communication and transportation hub, a large industrial center... okay, but when will the Soviets surrender, and under what circumstances? I personally don't know... I'm not quite sure what was going through Hitler's mind in early 1941... "gee, I wonder, if we capture Moscow, do you think the Soviets will surrender? Oh what the hell, let's invade anyways".