The under water navies are getting more and more prolific. I was on a US Navy missile sub in the Med in 1973 and it was crowded then. The seas around Japan and China have to be as bad or worse.
Everyone wants a piece of The action but South Korea getting in to it and reunifying with th Norks is a receipe for disaster. IMHO.
28k U.S. troops there. Time to fish or cut bait.