Well, look at it from China's perspective. They know that the U.S. would love to have a military presence on China's border so that we can threaten them more directly over their financial independence that we don't want them to have. The best location from which to do that is North Korea;...with the added bonus of using the ass-kicking of NK to scare other countries into compliance and whip up patriotic fervor and loyalty at home.

China is not going to allow that for one second, even if it means going to the mattresses to defend their spoiled little child monster creation that they are constantly embarrassed by.