I have a idea for this. Japan and USSR cannot attack each other until one of this happens:
- Japan only can attack USSR if Japan controls at least 7 VCs at start of combat movement phase
- USSR can only attack Japan if USSR controls at least 3 VCs and Germany + Italy control 0 VCs at start of combat movement phase
Attacking is optional when the conditions are done, and the pact is not broken until someone actually attacks the other, but then is borken forever
While the pact is valid, Japan and USSR cannot:
- Attack a land territory controled by the other (includes SBRs)
- Attack a sea zone that contains only units of the other (ex.: Japan cannot attack a lone soviet submarine)
Surface sea units block as usual
However, they can attack a land territory controled by a third, even if it’s only defended by pact units (ex.: Japan can attack Yunnan even if her only defense is a soviet stack). This represents expeditionary forces (in Yunnan case, you can say Japan was fighting maoist forces or such)
I wanted combine a easy non agression pact and giving more value to VCs. The reason for Japan conditions is that Japan would not attack USSR in real life until they beaten western allies (6 VCs means Tokyo, Shangai, Manila, Hawaii, Sydney, Calcutta). The reason for USSR ones is they didn’t attacked Japan until western axis was done