North Korea has never been an easy ally for the People’s Republic of China. With the execution of Jang Song-taek, Kim Jong-un’s uncle and supposed mentor, Beijing’s uncertain clout in Pyongyang is at risk.

“Dear Leader” Kim Jong-il has been dead barely two years, but his son appears to have turned politics there into blood sport. While family members, including Jang under both Kim Il-sung and Kim Jong-il, were commonly sidelined, they never were publicly executed.

Now the game has changed. Although Kim appears to be in firm control, the circumstances are extraordinary. A quick execution is as much a sign of weakness as strength, suggesting the need to dispatch a dangerous rival who might gather support. Undertaking a broad and deadly purge creates not only uncertainty but desperation, which might spark unexpected resistance.

As I recently wrote in US-China Focus:

The most obvious concern over the DPRK concerns a foreign policy which has gotten more erratic and confrontational since Kim Jong-il’s death. Kim regularly employed brinkmanship as policy, but always seemed to know just when to stop. Kim fils has demonstrated no such limits. His latest threat of war against South Korea went by fax to Seoul. The possibility of mistake or miscalculation seems much higher.

There also is rising doubt as to the PRC’s ability to offer a moderating influence on Pyongyang. China’s relationship with the DPRK never has been easy. Still, Chinese energy and food aid has been essential, and most recently Chinese investment has provided the DPRK an economic lifeline.

There has been a recent hardening of attitudes in the PRC. Nevertheless, until now the North continued to seek support from China. But now Jang is gone.

Jang was widely thought to play an important role in economic affairs and place greater emphasis on economic development, which probably meant support for economic liberalization.

Moreover, Jang had established a strong relationship with Chinese officials. Bilateral deal-making seemed to accelerate in Kim Jong-il’s final years, when Jang played an important leadership role. In 2012, the latter headed a large delegation which discussed expanding special investment zones with Beijing’s support. Many North Koreans linked to Jang were in business in the PRC.

It is widely presumed that Jang was removed for political reasons. Yet the bill of particulars included several economic charges.

For instance, Jang was accused of having “seriously obstructed the nation’s economic affairs and the improvement of the standard of people’s living.” Even more telling, Jang’s indictment includes the charge of “selling of precious resources of the country at cheap prices” and having “made no scruple of committing such act of treachery in May last as selling off the land of the Rason economic and trade zone to a foreign country for a period of five decades under the pretext of paying those debts.” Moreover, corruption was charged involving a 2011 project at Rason.

Of course, China is the “foreign country” cited.

The charges could merely reflect a “kitchen sink” quality, but they seem too specific for Beijing’s comfort. So far nothing has obviously changed. New contracts have been signed and one North Korean economic official announced “It’s just the same as before.” Still, inertia might continue to govern, with change to come. Zhu Feng of Peking University observed: “the negative impact must be tremendous.”

Chinese with whom I spoke in early December admitted that they could only speculate. But if the North really is targeting Beijing along with Jang, relations could deteriorate quickly.

North Korea’s urge to purge should prompt rethinking in Beijing about the North Korea “problem.” The PRC should explore options with South Korea and America, including taking a much tougher policy toward the DPRK in return for allied attention to Chinese concerns over economic costs, refugee flows, and security issues. The North’s neighbors should work together to ensure a stable and peaceful future no matter what.