You must rival the German Luftwaffe (air force) to ensure you have air superiority, which is important no matter what land doctrine you go down.In your national focus tree, you should go down the ‘Positive Heroism’ root as opposed to the ‘Collectivist Propaganda’ as you get Konstantin Rokossovsky (Armor Genius) and higher research reduction times, making you more advanced by the time you go to war in 1941.The Soviet-German Research Pact, Great Purge, and Molotov-Ribberntrop Pact must be followed, as you obtain a higher national unity, research bonuses on medium tanks, and take Eastern Poland after the Germans invade Poland in 1939.
