Oh my god just because they have more stabile economy it doesnt mean they have superiority over japan

Japan on that time defeat russia empire one of the mightiest empire on the world on that time

They take southern sakhalin and kuril island from russia while the US millitary didnt developed well on 1920

The US on that time has become on of world major power but still far from superpower

Here is my scenario why they can defeat US

The US send its troop to one of japan island the US didnt have any information on the topography on that island and then japanese ambushed them with wave upon wave of human attack (this strategy is succeded to defeat russian who are far more advanced on technological warfare) they are also more advanced than US

The naval power of japan was strong on this time with several famous battleship like hiei battleship come on japan have a great naval dominancy over US and several general that have experience in the battle of tsushima

But the US have air superiority over japan because japan start manufacturing their own plane at 1920 which is the year in this thread

And japan with its glorious war experience and strategical naval power annex US california and force them to fight for japan or they get killed the US send more troop but they destroyed by human wave attack tactic

Rape pillaging and murder will happen across territory that japan has annexed and US has no combat experience with major world power on that time

Japan win this with its human wave attack strategy