It's not 1945 anymore. Nobody in Washington has any qualms about Japan building up its military strength with anything short of nukes. The post-war constitution

It's not 1945 anymore. Nobody in Washington has any qualms about Japan building up its military strength with anything short of nukes. The post-war constitution and pacifist values imposed by the Allies on Japan actually took too well, and the Japanese people remain more skeptical of the wisdom a more militarized Japan than either the current Japanese PM or Washington. Japan has little to gain from going on another rampage through Asia conquering stuff. Even if you ignore that annexing other countries tends to make you an international pariah these days (see Russia in eastern Ukraine), everyone near them either has nukes (Russia, the PRC, and the DPRK) or is in some form of alliance with the US (the ROK and ROC).