This disturbing event raises the question of whether President Donald Trump’s new strategy on North Korea is working. Since his summit with Chinese President Xi Jinping in Florida in early April, Trump has made a dramatic shift in his approach to containing the North Korean threat. Instead of issuing warnings of unspecified punishment and actions, Trump appears to have outsourced the North Korean problem to China, counting on Beijing to pressure Pyongyang to stop its dangerous weapons programs.

A practitioner of transactional diplomacy, Trump has made an advance payment for China’s potential cooperation. He has jettisoned the strident anti-China rhetoric that marked his populist campaign and backed away from labeling China a “currency manipulator.” He openly praises Chinese leader Xi Jinping as “a great guy” and touts his excellent relationship with him.

Unfortunately, if Trump believes that Xi will solve his North Korean problem for him, he would be seriously mistaken. In containing the grave threat from North Korea, China can be a partner and play a useful role, but putting all the hopes on Beijing would be a risky gambit.

To be sure, China has its own reasons to moderate North Korea’s behavior. Kim Jong Un’s provocations de-stabilize East Asia, China’s immediate neighborhood. Worse still, such dangerous acts have given the U.S. a perfect pretext to strengthen its military capabilities and introduce anti-missile systems into the region that could threaten China’s security.

However, Beijing’s interests in the Korean peninsula diverge fundamentally from those of Washington. For China, North Korea is a valuable strategic buffer. It may be a rogue state ruled by a 33-year old thug. But at most it is a nuisance since nobody in Beijing seriously believes that North Korea has the capacity or intention to invade China or undermine the rule of the Chinese Communist Party (CCP). In contrast, the U.S. presents a far more lethal threat to Chinese national security and the CCP’s survival. It would be pure folly for China to help its geopolitical adversary to destroy its strategic buffer. The recurring nightmare in Beijing is not North Korea’s acquisition of intercontinental missiles tipped with nuclear warheads, but the arrival of American troops across the Yalu River in a reunified Korea.

Beijing’s strategic calculus thus dictates that it will pressure or bribe North Korea to restrain its behavior but won’t adopt truly punishing sanctions that could precipitate a regime collapse.

Needless to say, Kim Jong Un, like his father and grandfather, understands Beijing’s dilemma completely. He knows that China needs him more than he needs China. His father and grandfather repeatedly called China’s bluff and each time China blinked. We may recall that in October 1950, when faced with the total destruction of the Kim regime and war with the U.S., Mao Zedong chose the latter even though it would cost more than a million Chinese casualties.

As long as China continues to regard North Korea as a strategic asset, it will not do what Trump wants.

Most likely China will meet Trump half-way. Beijing will start turning the screws on Pyongyang. China, for example, has stopped taking coal import from North Korea. We should see tighter enforcement of restrictions on exports of dual-use technology and equipment to North Korea. The import of North Korean labor will be curtailed, but not totally suspended. But other vital support for North Korea, such as oil shipment, banking, and telecom services, will likely continue.

Beijing hopes that these measures will demonstrate to Trump that it has done its best to fulfill its part of the deal. If it has not succeeded in bringing Pyongyang to heel, it should not bear the blame. Beijing would claim, not without justification, that it has done enough, and the U.S. should step up on its own to entice North Korea to the negotiating table. In this scenario, Trump will have less leverage with China and face painful choices. It would be hard for him to hold China accountable since Beijing will insist that it has done all it can. Should Trump then negotiate with North Korea (an outcome China prefers because it will shift the onus to Washington) or seriously prepare for military options?

If last weekend’s North Korean missile test is any indication, it suggests that Trump’s outsourcing strategy is not working and will unlikely succeed. He should start thinking of alternatives.

Minxin Pei is a professor of government at Claremont McKenna College and a non-resident senior fellow of the German Marshall Fund of the United States.