kernals12
Banned
With no other countries stopping them, they could annex most of China including resource rich Mongolia.Only if they somehow were able to keep Korea as a colony. Let's assume a population of 150 million (no Pacific War, Taiwan, Karafuto, and South Pacific Mandate still part of Japan). That would give an GDP of about 3 trillion USD, between OTL France and Germany but significantly less than modern Japan. They'd need to spend over 10% of their GDP on the military to match US spending, and they're still resource poor. Compare that to the USSR with a significantly larger population and massive amounts of resources. The main advantage is that they can afford to build up a large navy as unlike the USSR, Japan is naturally a naval power.
If they somehow were able to keep Korea, though, then they'd be a lot more of a threat, given Korea adds a significant amount of people and more importantly, a massive amount of resources.