My own thoughts.
As a protectorate of China, North Korea's association does not appear to be that of an obsequious nature. The unpredictability of this relationship would not however be tolerated by China except as North Korea serves to buffer China from South Korea, an entity supported by as strong a nation as the United States.
China up to the present time seems to have keep separate her diplomatic manifestations of her insular nature as it affects South Korea and her trade and financial involvement with the US.
Although China for the moment would be content with the status quo, North Korea apparently independently acting as an unruly member of the family has been making this relationship more and more difficult for China.
China understands that world would want her to exercise more control over North Korea's unwarranted behavior, however, China does not want to appear to be yielding to outside pressures. She also wants to eliminate trouble in this area while she pursues her international economic goals.
Nor does China's established association with North Korea permit China to exercise, even in appearance alone any feudatory restraint over her protectorate. Yet only China's ability to exercise control over North Korea's actions at this time can prevent a serious, perhaps prolonged conflict taking place near her borders.
China is embarked on economic development and on establishing trade opportunities with the rest of the world, significantly separating herself from her insular nature for the time being, therefore, this situation comes at an awkward moment.
Yet we must look to China to assist us and to work with us in removing the chances of our own involvement, especially in a military conflict with North Korea. We don't know how China would react to a war taking place at her door step that brings one of her most important trade partners in conflict with her neighbor and protectorate.
Will this incite China's insular nature and cause her to take military side with North Korea against her own economic interests? And in the end what is there in it for her? And what is there in it for us? What is there in it for South Korea and for North Korea?
China and US must resolve this issue and bring both North and South Korea into this agreement. The central problem is the hatred that both South and North have developed toward each other and especially the loss of status that North Korea feels.
Perhaps some form of economic organization involving North Korea and both China and US might do it, as it seems that restoring North Korea's feeling of dignity as a nation is key to this issue.
This may for the moment lessen the disturbing nature that both North and South Koreans have developed toward each other.
We can support South Korea by showing military presence without engaging militarily. It will be up to China to lead in finding a way for getting North Korea to restrain herself on a more prolonged basis.