Yet despite such tensions, Beijing has failed to put real pressure on Kim, at least until very recently. But China’s call for more negotiations is best seen as a tactic to preserve the status quo, whereby endless negotiations absorb all of Washington’s energy while doing nothing to actually resolve the crisis. Kim and his father before him used all previous negotiations as a respite to push forward on the nuclear and missile programs, and there is no reason to think a new round of negotiations will have any different result.
For years, observers in Asia and the United States have claimed that China “holds the keys” to solving the North Korean crisis. If so, Beijing has once again shown its disinterest in doing so. More likely, it has less influence than the world thinks, and has as few ideas for dealing with Kim as do the Americans. Nonetheless, China could help in controlling North Korea if it decided to work with an equally realistic United States to contain and deter Pyongyang. There is little reason to believe it will do so.
http://nationalinterest.org/feature/how-china-can-really-help-north-korea-22163?page=show