China needs to keep North Korea in check, as much to reassert its own power in the region as to maintain stability

China holds the trump card when it comes to curbing North Korea’s nuclear ambitions. As the source of virtually all North Korea’s oil and half its food, Beijing exercises life-or-death power over its protectorate as much as it did in 1950 when Chinese “people’s volunteers” saved the fledgling Democratic People’s Republic of Korea from annihilation in the Korean war.

Now, while China has joined in condemning Pyongyang’s latest nuclear test, the question is: To what degree are the Chinese willing to back up their words with deeds?

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Yes, China has supported United Nations sanctions after previous nuclear and missile tests – and might support still more sanctions. No, China has not enforced them particularly well while critical goods move from China to North Korea, through private entrepreneurs as well as government agencies.

The Chinese are as puzzled as the rest of the world about what to do about North Korea. They, too, encounter high obstacles to persuading the leaders in Pyongyang to give up or scale down their nuclear and missile ambitions.

The Chinese were reportedly taken aback when they heard the all-female Moranbong troupe from North Korea would feature images of missiles in its programme in Beijing last month. When high officials said they would not grace the group’s show with their presence, the troupe was called home without giving a single performance.

As for the idea of Kim Jong-un making his first visit to Beijing since taking over from his late father, Kim Jong-il, in December 2011, how can China entertain, much less influence, the young leader when he is clearly not open to advice?