http://en.wikipedia.org/wiki/Suez_Crisis
Putin is trying to go all-in with his last few chips. If he succeeds, he'll be in the game for a few more rounds. If he fails, he'll be out.
Hitler had allies. He had what was when he took power the best mathematics universities in the world (with comparable success in other areas; he eviscerated German academia, though), and (IIRC) the second or third-largest economy. Putin has a doomsday device that he doesn't actually want to use.