Well. I’ll believe that when I see it, via Reuters:

China declared a “red line” on North Korea on Saturday, saying that China will not permit chaos or war on the Korean peninsula, and that peace can only come through denuclearization.

China is North Korea’s most important diplomatic and economic supporter, though Beijing’s patience with Pyongyang has been severely tested following three nuclear tests and numerous bouts of saber rattling, including missile launches.

“The Korean peninsula is right on China’s doorstep. We have a red line, that is, we will not allow war or instability on the Korean peninsula,” Chinese Foreign Minister Wang Yi told reporters on the sidelines of China’s annual largely rubber-stamp parliament.

Wang called upon all parties to “exercise restraint”, adding that “genuine and lasting peace” on the peninsula was only possible with denuclearization.

North Korea doesn’t have many allies, but they managed to irritate even the Cubans with some of their irrational temper tantrums, and China especially has not been pleased with their ludicrous nuclear antics of late. They’ve long since tired of constantly playing the NorK’s babysitter in the region, but still — for awhile now, China has been pondering getting more forcible with North Korea in theory while continuing to coddle them in practice. As Jonathan Pollack explained at the NYT in January shortly after Kim Jong-Un had his Communist Party elder-statesman uncle executed seemingly out of the blue:

The Kim dynasty intends to keep China in the dark as fully as it can. Chinese leaders, including President Xi Jinping, voice periodic frustration with North Korea, but none seems able or willing to translate Pyongyang’s ever increasing economic dependence on China into meaningful influence. …

Some argue that the legacy of the Korean War weighs heavily on the minds of more traditional constituencies within the Chinese Communist Party and army. But deeper, current anxieties also inhibit Beijing. China fears that extreme actions by an unpredictable, heavily armed neighbor with a xenophobic leadership could trigger a larger crisis on the peninsula that would quickly involve China. Lacking realistic options to control North Korean behavior, China prefers instead to avoid doing anything that might alienate Pyongyang.

While China insists that it wants normal state-to-state relations with North Korea, it is not prepared to impose conditions on its isolated, troublesome neighbor, much less undertake a larger reassessment of its policies. As a consequence, Mr. Kim sees little reason to follow China’s advice, and he will continue to zealously guard against Chinese influence on the North.