That is an awesome rule. That is perfect. Historical and accurate.
One idea about IL’s reasoning that makes sense that he has not to my knowledge expressed. I am a history buff. I read a lot and watch the History Channel and Military Channel. I have always had the sense that Japan, after 1939 did not want war with Russia. It needed the resources of the islands. Oil, rubber, ect… Without that it could not take out China much less Russia. The traditional axis and allies starts out with Japan having those resources. Once it got them, they might have decided to invade Russia. But why didn’t they. They spent huge resources attacking the US, when they could have assitted the Germans invading from the rear. Why didn’t they.
How about this. Germany was to Japan what Russia was to US. The enemy of my enemy. Nothing more. They wanted Germany to slam thier head against Japan while they grew stronger and stronger. So they hoped by attempting to take the entire Pacific. Invading Russia from the rear risked Hitler being successful and getting to Moscow first making him King of the Land. Like all dictators and thieves in an enemy of my enemy alliance, each tries to play it out so they end up on top.
Japan wanted the west to be in a protracted war while they prospered in an “Asia co-prosperity something or other”.
Just my take on all the facts and opinions on the facts I have heard throughout my time.