That was and is an unholy alliance that would never work. We should be thankful that those fuckheads hate each other because if they could ever band together we'd be screwed.Only way a campaign into Russia was going to work would have been to have Japan focus on Russia as well instead of them poking Uncle Sam. Heck if they were smart they would have worked China into the mix. Japan hating the Chinese made that moot.
Russia wouldn't have been able to defeat Germany coming in from the left, Japan from the right and China right up the middle.