ORIGINAL: Knavey
AI or PBEM game?
Huge difference.
That is the key point. Against the AI its do-able. In a PBEM I would strongly advise against it.
Just to prove the point, I am currently in a AI game where I have invaded Russia. You really want to know where the best early war allied fighters are? They're sitting on the airfields at Vladivostok. Not only are they holding their own, they are ripping the JAAF fighters to shreds and have air parity with the Zero's.
My advice...only invade Russia in the AI. Forget about it in a PBEM.