It Makes a Difference to the Sheep

CHINA AND THE TWO KOREAS. A reasoned examination of the relations between China and both North and South Korea by Denny Roy can be found here. A portion:

Beijing and Seoul enjoy warming relations and great potential for economic cooperation. Based on current trends, the Chinese have reason to hope that in the long term Seoul will have a closer and stronger relationship with China than with the United States.
Pyongyang remains a troublesome ally for China, refusing Chinese advice to commit itself to the Chinese model of economic liberalization and integration with the global economy, and seeking improved security through risky confrontational tactics such as developing a nuclear weapons program.
Chinese strategists are more amenable than in the past to the idea of a united Korea under Seoul’s control. The satisfactory and improving relationship with South Korea partly accounts for this, as does the growing conviction that China no longer needs a buffer state. Nevertheless, the Chinese generally fear the risks and uncertainties of the transition to a united Korea and are not inclined to campaign for a dramatic change in the status quo.

In addition, one wonders whether the present scuffle over the identity of Koguryo might have an impact on China's reluctance to encourage a unified Korea (once unified, Korea can then turn to other "unfinished business").

The article also argues that the U.S. shouldn't expect much in the way of Chinese assistance in its current non-proliferation crusade in North Korea:

Some Americans believe China is able to dictate policy to Pyongyang, if for no other reason than North Korea’s dependence on China for much of its food and energy supplies. Given this dependence, China ought to be able to force North Korea to meet any demand by threatening to cut off these vital supplies. It may follow from this line of reasoning, then, that North Korean failure to meet U.S. demands for a resolution of the nuclear weapons crisis indicates the Chinese are not interested in denuclearizing North Korea. This, however, is an unrealistically high burden to place on Beijing. First, the Chinese are careful not to pressure Pyongyang too hard for fear of triggering a collapse of the North Korean state, with all the problems this would entail for China. Second, despite the “as close as lips and teeth” rhetoric since the Korean War, Sino-North Korean relations have been severely strained on several past occasions. Pyongyang has shown it is not afraid to snub the Chinese if they are insufficiently supportive of North Korean interests. The Chinese realize that if they are too pushy they could lose all their influence with Kim’s regime.
Furthermore, many Chinese would have difficulty accepting cooperation between their government and the United States—a country so widely suspected of seeking to repress China and dominate Asia—against North Korea, a country for which so many Chinese spilled their blood in the common cause of opposing American encroachment. Opinion polls suggest Chinese overwhelmingly side with North Korea rather than the United States in the current dispute, even if most Chinese are also against getting involved in another Korean war.

Where has this kind of reasoned analysis been the last several months?