China's estrangement from North Korea continues to fester and deepen. Following protracted negotiations in the aftermath of Pyongyang's fourth nuclear test and subsequent satellite launch, the U.N. Security Council has imposed far more severe restrictions on North Korean trade, finance, and maritime activities. The resolution—which passed on March 2 and for which China was a key drafter—portends a much edgier and uncertain relationship between Beijing and Pyongyang.

Though there are ambiguities and loopholes in the criteria and enforcement provisions governing the resolution (UNSCR 2270), the new sanctions have much sharper teeth than previous resolutions—and China has unequivocally pledged to uphold the letter and spirit of the council's decision. Even before the resolution passed, South Korean and Chinese media reported that financial transactions in the city of Dandong (where most border trade takes place between China and North Korea) had been sharply curtailed.