Why China Supports New Sanctions Against North Korea

International pressure on North Korea has ratcheted up in recent days, as the U.S. imposed new unilateral sanctions and China began taking steps to implement a strict, new United Nations Security Council resolution.

But while the U.S. has few economic ties with North Korea to cut, China has plenty of screws to tighten. And so whether international sanctions work or fail may depend to a large degree on how strictly China implements them.

Beijing has begun instructing Chinese banks, ports and shipping and trading companies doing business with North Korea to implement the U.N. resolution to the letter.

China's U.N. Ambassador Liu Jieyi speaks with U.S. Ambassador Samantha Power before the Security Council vote on sanctions against North Korea on March 2.

Don Emmert /AFP/Getty Images

Adam Szubin, the Treasury Department's acting undersecretary for terrorism and financial intelligence, tells NPR that China is taking this very seriously.

"I know from my meetings here in Beijing that my counterparts have very much taken the resolution to heart," he says.

Szubin, who visited Beijing this week, says the new sanctions will hit hard enough to change Pyongyang's "decision-making calculus."

The new U.N. resolution is not just "adding a few new companies to a sanctions list or a few new North Korean officials," Szubin says. Instead, it targets "every major aspect of North Korea's access to international shipping, international banking [and] international trade to develop revenues for its missile and illicit nuclear programs."

Although China appears committed, the sanctions put it in a tough spot.

First, says People's University international relations expert Cheng Xiaohe, some Chinese companies are going to take a hit to their bottom line. China-North Korea trade was worth $6.39 billion in 2014.

"At the same time as we protect our national security interests, we must be prepared to sacrifice some of our own economic interests in order to accurately target North Korea with sanctions," he says.

Cheng says the U.S. has its work cut out for it, collecting intelligence on the hundreds of Chinese firms doing business with North Korea, and on North Korean firms adept at concealing their business dealings behind fronts and shells.

And if Chinese firms are found to be violating the U.N. resolution, Cheng points out, they could themselves face sanctions.

"This could create new frictions between the U.S. and China," he warns. "I hope that the U.S. will think carefully before it uses this big stick to crack down on Chinese firms."

Cheng notes that China continues to supply North Korea with crude oil as humanitarian assistance. The sanctions allow this, even if North Korea may be able to refine some of the oil for military uses.

China says neither a humanitarian crisis nor regime collapse are acceptable outcomes for North Korea. But Zhang Liangui, a veteran North Korea watcher at China's Central Party School in Beijing, says that at the end of the day, China cannot save North Korea from its fate.

"If North Korea is going to collapse," he says, "no external force can prop it up. Frankly speaking, whether it collapses or continues to develop will mainly depend on its own domestic and foreign policies."

North Korea's most recent nuclear test has put Beijing on the back foot, undermining its diplomatic ties with Seoul and raising the possibility that the U.S. could install missile defense systems in South Korea.

Cheng Xiaohe says Beijing doesn't like this — but there's not much it can do.

"China has neither the ability nor the political will to give South Korea the security guarantees it seeks," he says. "But the U.S. does."

The setbacks have led some Chinese observers to wonder, "Has China's North Korea policy failed?" — as the official People's Daily newspaper recently asked in an online headline.

Zhang Liangui says the possibility of failure is not one that Chinese diplomats dare admit. Then again, Zhang says, for the past two decades, no country has succeeded in keeping the Korean peninsula nuclear-free. North Korea's current suspected stockpile is estimated to include 10 to 16 nuclear weapons.

"The way this situation has developed is a collective failure for all of us," he laments, "a failure for the entire international community, including the United Nations."