China's changing role in the world has meant its approach towards ally North Korea has had to evolve. Its support of a UN resolution condemning the country's recent rocket launch and tightening sanctions makes plain its willingness to accept its responsibility. But there is only so much Beijing can do to end the isolationist country's threats and intransigence. Lasting peace and stability in Northeast Asia ultimately rests on Pyongyang also being open to compromise.
A change of leadership brings the chance to review and recalibrate policies. Kim Jong-un's succession as North Korea's leader 13 months ago brought hope of reforms. But beyond promises and a new governing style, little seems different.
Pyongyang reacted to the latest UN resolution with predictable anger, pledging to strengthen military and nuclear capabilities. A third nuclear test and more missile launches had already been foreshadowed.
There are also new leaders in China and South Korea - incoming president Xi Jinping and his recently elected counterpart, Park Geun-hye. Both countries face economic challenges and the leaders have reached out to one another for support; China's backing of the US-sponsored resolution was in line with the push to improve relations. But it also sends a strong message to Pyongyang that Beijing's patience is wearing thin. State media's warning that Chinese aid to Pyongyang will decrease if it goes ahead with another nuclear test reinforces it. Continued pressure on North Korea to end its tests and sabre-rattling, embrace globalisation and move towards the Chinese model of socialist transition would be constructive.
Xi has assumed power with a desire to make China stronger. Neighbouring North Korea, the source of growing numbers of refugees fleeing poverty, hunger and oppression and a persistent threat to the region's peace and stability, could easily defeat that goal. China has to be more assertive in convincing North Korea to open up. But Kim has to grasp the reality that it is in his country's interests to change its ways.