I was stationed in Japan for two years in the Navy and have seen some of their naval forces up close. Believe me, the Japanese Maritime “Self-Defense” Force could easily take on a lot of the world’s navies.
I was Army and concur with your assessment. Japan is no joke militarily and their economic and manufacturing base is powerful.
Trump’s instincts on how to contain China are pretty good and he has a kindred spirit in the prime minister of Japan.