Now Xi, with his authority unquestioned, his foreign policy team in place, and a DPRK-Republic of Korea (ROK) summit imminent, has seized the moment to reassert Chinas pivotal role in managing inter-Korean tensions. Souring relations and a brewing trade war with the U.S. probably also shaped his calculus. North Korea is far from being Chinas puppet, but it is an important card Beijing has to play in its intensifying strategic competition with Washington.
In an unusually detailed report, Chinas state news agency Xinhua said the meeting was unofficial and a strategic choice, and that Kim came to Beijing out of moral responsibility signalling that relations are frosty but fixable. According to that report, Xi also told Kim what he now must do if he wants Chinas help: meet regularly at the level of decision-makers, communicate early and often, prioritise economic development, promote people-to-people exchanges, and agree to denuclearisation of the Korean peninsula as a long-term goal. One Chinese proposal not in Xinhuas report may have been to host some forthcoming meetings. Symbolically and practically, that would cement the Middle Kingdoms position.
If Xi gets his way, by years end Korean peninsula talks could be back in a dialogue framework shaped by China. North Korea would become a problem to be managed but not an imminent threat, denuclearisation again would be a distant political goal, and sanctions would evolve into an adjustable valve to manage pressure on Pyongyang. Order under heaven, from Chinas perspective. But while that may be Beijings preferred route, the journey ahead is far less certain than that travelled by the train that brought the DPRKs ruler to his first summit, and many factors could knock diplomacy off the rails, not least Kim Jong-un and Donald Trump themselves.
Taking over the control of NK economy will help greatly. If NK population begin to feel that their economic well-being has dramatically improved after China's economic control, China can begin to erode the political base of Kim Jong-un and his ilks. A slow takeover of NK is probably China's goal, and Kim is likely to know it. He will try to resist it. I think China sees that his option is markedly narrowed due to Trump's aggressive policy.
At the same time, China's policy would be also geared to use NK issue to fight off Trump's trade offensive to China, threatening to undermine his goal of NK denuclearization unless Trump relents. I think Trump has to make decisive move in next few months.