the japanese military was actually very, very lackluster in ww2
even in the midst of the great depression, the US was still more financially, industrially, and militarily capable of waging war than japan. its numbers may have been large but a supreme lack of disconnect between its branches (a combination of several factors like aging leadership and stagnant military tradition) was its true achilles heel. japan was the first asian country to westernize, so its military was definitely better than that of its neighbors like china and korea (the latter of which japan annexed), but it was still far behind those that existed across the pacific or in europe. japan's lack of resources and industry meant armored units were basically impossible to sustain, and planes were made a rare commodity after the american embargo, so japan's only real saving grace was its navy (which was fairly outdated) and its millions of captured weapons, to which the jingoistic empire used to terrifying effect in battles like iwo jima.
one thing that remains constant between the empire of japan and the japan today is that they simply don't have the resources, economy, or industrial capacity to sustain a protracted conflict. the empire of japan was capable of doing what they did because of an intense campaign of indoctrination and exploitation at home and abroad. japan today cannot do either of those things.
