Chinese foreign policy currently appears bold and assertive, but on the peninsula China’s stance remains exceedingly risk-averse. The question is why Beijing continues to exhibit such caution, even outright timidity, toward the North.

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.