Then why stop there?
Why not argue to allow the Russians to attack Germany on R1
Why not argue to allow USA and UK to attack Japan on US1?
Why just argue for historical ‘what-if’ and only consider japan not being able to attack Russia before turn 4.
My argument is in all three cases their remains considerable historical reasons to support these rules to deny them based on historical facts. In most cases the influence that denies this is based on events that happened before Sept 1939
If you want any one of them, then you must include them all and consider a broken game to follow.
Even based on the setup, which is historical it is not even remotely possible for Japan to even be able to attack Russia before the second turn unless you like 1:3 odds. This is just like having Germany try invading Russia when France has not even been attacked. The possibility of this given the setup is also zero as it was historically.
ON J2 you could get close to a little less than 1:2 odds, and by turn J3 you would be ready for an attack. Once you attack Russia they double in income ( like from 20 to 38 IPC) while Japan is at 17.
Japan needs at least 1-3 turns to get enough IPC to get to close to 25. This will be at the expense of China and FIC.
If you play the game and make your own house rule and allow this, Japan will lose her game because on turn 4 USA enters no matter what Japan does. Japan cant fight a 3 front war in my game. IN my game if she does this they will lose like 101% of the time.
Thats why in addition to other historical facts that it is not allowed, because i don’t like players doing silly things and ruining the game with trying “glitches” to circumvent the system. My system in Global 1939 has considered all the possibilities of these personalities, because my play-test group has members who love nothing but finding glitches. One of them named Steve has this habit of starting invasions of every inconceivable manner, so knowing this my design process drew experience from this behavior.