I don't think Korea has changed much, the leadership is exactly the same as sixty years ago.
I suspect some collusion between China and North Korea, this might be a way to find out how the US, Japan and South Korea respond to threats.
China wants to make a real estate grab out of the ocean , weirdly willing to kill off a lot of the fishing to make it happen.
North Korea is making a play at reducing the American presence by waving a new stick, hoping we count them crazy enough to forget that everything they do to us we can do to them five times over.
Perhaps this is just worth a try, China and North Korea can both back down or can try to make some trade in the deal, they don't need to back down until the fuse is very short, so why not test our nerve ?
