John J. Tkacik, Jr. explores "who's behind China's north Korean policy...and it's not Chinese diplomats:

Indeed, the real players in Beijing’s Korea policy are the PLA leadership. There is no doubt that the PLA is in close contact with its North Korean counterparts. Article IV of the July 11, 1961, military pact (the “Treaty of Friendship, Co-operation and Mutual Assistance between the People’s Republic of China and the Democratic People’s Republic of Korea”) obliges Korean People’s Army (KPA) commanders and top Chinese generals to “continue to consult . . . on all important international questions of common interests.” In return, China is to “render . . . every possible economic and technical aid in the cause of socialist construction” including “scientific and technical cooperation.”

Just prior to the opening of the Beijing multilateral talks on North Korea’s nuclear weapons program in April 2003, North Korean Colonel General Jo Myong Rok camped out for four days in Beijing where he met with every top PLA leader. In late August 2003, just before the Six-Party talks began, the PLA’s top political commissar, General Xu Caihou, made a hurried visit to Pyongyang. Those talks were a disaster—at least from the American point of view—as were all previous and subsequent sessions of the talks.