Chinese experts have long maintained that the West overstates their country’s influence over North Korea, especially in the Kim Jog Un era. They acknowledge that China has economic leverage over Pyongyang, but at the same time point out that China is boxed in because its ultimate goal is a stable North Korea—and because any international pressure could lead to instability on the Korean Peninsula, Beijing is reluctant to take forceful action.

“It is difficult to estimate China’s influence over Pyongyang,” Lu Chao, director of the Border Study Institute at the Liaoning Academy of Social Sciences, a government think tank, told NK News in an interview in 2015. He said that in the era of Kim Jong Il, Kim Jong Un’s father, “the two countries followed the practice of notifying each other on serious issues. But the ties are going through a relative low point, and there seems to be no such practice now.” In an interview in May with the Globe and Mail, Luo reiterated those comments: “Frankly speaking, we are right now at the lowest point in the relationship between China and North Korea.”

Americans who have dealt with Chinese diplomats on North Korea empathize, but say there’s no question China still wields enormous influence on the leadership in Pyongyang.

“I think it’s a fair statement that China is experiencing a significantly different dynamic with Kim Jong Un than with his predecessor, which should be extremely concerning to all of us, and which I think is legitimately concerning to Beijing as well,” said David Pressman, a former U.S. ambassador to the UN for special political affairs during the Obama administration. “I think there was a time when there was more predictability in the relationship between China and North Korea and the leadership of both countries.”

But Pressman, who is now partner at Boies Schiller Flexner LLP, added while China has the “ability to influence” North Korea’s calculus on its weapons programs, “we’re not even seeing a significant effort from Beijing to attempt to do that.” He noted that in early 2016, China was willing to adopt strong sanctions against North Korea at the UN, but “proved systematically prepared to look for excuses to not implement and not force the measures, including the measures that they’ve supported, being implemented.”

Indeed, at the time the UN imposed sanctions—which, among other things, prohibited North Korea’s sale of coal—China insisted on an exemption that permitted Pyongyang to export coal to facilitate the livelihoods of individual North Koreans.

“What the Chinese then proceeded to do with the livelihood exemption was funnel enormous amounts of coal trade under the guise of this exemption,” Pressman said. “So they were prepared to support the political message of banning the export of coal, but they weren’t prepared to deliver in practical terms that would actually make the North Korean regime feel some financial pain. And for sanctions to work, obviously that has to happen.”