Or incredibly bad decision-making on the part of a possibly barbituate-crazed leader; "let's break our pact with previously-friendly Russia and invade them, learning nothing from Napoleon's extreme failure in Russia. Fighting a war on two fronts is a great idea!" Who knows; if Germany hadn't gone to war with Russia it's possible that they'd still have today much of the land they took in 1939-1941.
That's possible. On the other hand, who would trust Stalin as far as he could throw him? Ironically enough, the same strategic mistake did in another megalomaniac dictator more than a century before. Don't start a land war in Russia, unless you're Mongols.
Germany started WW1 because it could not let Russia mobilize. You leave your precious flank open, and suddenly you start speaking Soviet, as mentioned.
