Great to several perspectives on this subject. I would like to see it run through a couple times with full out war, with the exception of Russia I guess, starting at turn 1, then turn 2, then turn 3. I understand the point of stalling USA for a few turns globally, but if Russia is only having a minimal impact on the pacific with its 18 inf then I don’t see why not go balls out with Japan on turn 1. You can take several chinese territories, Hong Kong, Phillipines, destroy 3 allied transports and other sea vessels, and have a mainland factory being constructed. Even if you bring the USA into the war turn 1, they still have to build on their first turn, then move ships into forward positions on turn 2 and begin actually attacking on turn 3. If the Japan player plays like they would have if pacific is its stand alone game, then they should be applying enough pressure to keep China and ANZAC basically screwed the entire time, while also keeping India and west coast USA in check.
I do like the comments but I really want to try a turn 1 Japan attack with that Pacific only mentality. I think it could do enough to help Germany and Italy by making the USA put tons of cash into the pacific.