> In WW2 Stalin initially made a pact with Hitler while all the while knowing Hitler would violate it and invade anyway. Stalin just used it to buy time to ramp up the Soviet military. From what I recall it's likely Hitler assumed this as well and used the pact to delay dealing with the Soviets militarily and focus on his Western front to snatch up as much of Europe as possible.

Not true at all. 1) Stalin was caught off guard by the invasion. We know this because he holded up in his private residence for a few days afterwards until the Politburo came visited him and asked him what he was going to do.

2) The Russian military was not tactically or strategically ready when the Germans attacked. We know this because the Russians lost millions of soldiers by encirclement in the days and weeks after the start of the war. If Russian military had been ready, it would have been in much better position(s).

3) Stalin had purged thousands of quality officers and NCOs from the Russian military. You can't have a good military without a professional, respected and well maintained NCOs core. If Stalin thought the Germans would really attack, he would have built up a professional officer and NCO core.

The three things that really saved Russia are January, February and the willingness of the Russian people to do anything for Russia, regardless of who is in charge.