North Korea

The North Koreans scare the crap out of the Japanese. Just imagine such a tightly packed island, that could easily get hit by conventional missles from a very close neighbor. We dont have that problem. (Not to mention that the Japanese did some horrible things to the Chinese and Koreans during WWII). So the Japanese are terribly concerned. And if they are concerned, we are concerned.

I think the Chinese do not have a problem with the N. Koreans causing the Japanese major anxiety. The Chinese do have a problem if this causes us to become aggressive... To give us an excuse to load the Japanese up with some anti-missle system, or worse, for us to start working intensely on anti-missle systems that actually work. The Chinese do not like that aspect at all.