It is no secret that the United States wants China to take a firmer stance toward its troublesome North Korean ally. That was true even before the North’s satellite launch/long-range ballistic missile test. And Chinese officials may be receptive to the argument that steps need to be taken to rein-in Kim Jong-un’s regime, even at the risk of destabilizing his government. But as I point out in a China‑U.S. Focus article getting Beijing to accept the risks entailed in becoming more assertive toward Pyongyang will require some major changes in U.S. policy.

At a minimum, Washington will have to respond favorably to China’s long-standing demand that the United States be willing to engage North Korea in wide ranging negotiations to reduce tensions on the Korean Peninsula. Chinese officials are increasingly uneasy about Pyongyang’s behavior, especially the regime’s continued defiance of China’s warnings not to conduct more nuclear weapons or ballistic missile tests. But Chinese policymakers also still cling to the belief that much of North Korea’s belligerence and recalcitrance is the result of the U.S.-led campaign to isolate the country. Only by offering a comprehensive settlement to Pyongyang to finally end the state of war on the Peninsula, lift most economic sanctions, and establish diplomatic relations, will Washington convince Beijing that it truly seeks to an equitable outcome.

If the United States makes such a generous offer and Pyongyang rejects it, an already uneasy China will be even more impatient with its North Korean ally. And China is the one country that can inflict real pain on Kim Jong-un’s regime. Beijing supplies North Korea with a sizable portion (by some estimates more than half) of its food and energy supplies. If China severed that link, North Korea would soon face an economic and social crisis. Beijing has been reluctant to take that risky step for two reasons, however. First, it could well trigger chaos in North Korea, perhaps bringing down Kim’s regime and leading to massive refugee flows out of North Korea into China. That is no small concern, but in addition to that headache, Chinese officials worry that the United would seek to exploit such a situation to its geopolitical advantage.

For all of its annoying behavior, North Korea is an important buffer state to China, separating the Chinese homeland from the U.S.-led alliance system in East Asia. Destabilizing North Korea carries the inherent risk that China might then confront a united Korea on its border—a united Korea in a military alliance with the United States. Even worse from China’s standpoint, it might have to deal with the presence of U.S. air and naval bases in what is now North Korea. The buffer would be gone.

Even verbal assurances that the United States has no plans for such bases would provide scant comfort. Chinese leaders are fully aware that U.S. officials promised their Russian counterparts when the Soviet empire in Eastern Europe evaporated that NATO would not expand eastward. Today, all of those nations are members of the U.S‑led NATO, including several directly on the border of the Russian Federation itself. Moreover, the United States is building up its forces in the eastern members of the alliance.

Chinese leaders are determined that nothing comparable will take place in Northeast Asia. They will want something more tangible than an easily forgotten paper promise. Fortunately, the United States can offer that more tangible guarantee. Washington’s military alliance with South Korea is a Cold War dinosaur. It was formed at a time when South Korea was poor, weak and war-ravaged. Worse, that weak South Korea faced a heavily armed North Korea fully backed by both Moscow and Beijing. South Korea could not have survived without U.S. protection and massive U.S. aid.

How times have changed! The last thing that either Moscow or Beijing want is another war on the Korean Peninsula. They have utterly no interest in backing such a venture by their nominal North Korean ally. Indeed, Beijing especially is developing is significant economic relationship with South Korea. And China is wise to do so. South Korea now has twice the population and an economy 40 times the size of North Korea’s. Seoul can afford to build whatever forces it deems necessary to deter North Korea, or failing that, to utterly destroy an attacking force. Washington should have terminated the alliance with South Korea years ago. U.S. leaders should make it clear now to Seoul (and Beijing) that we will be doing so over the next few years.

That concession must be made with eyes open. The withdrawal of U.S. forces from the Korean Peninsula means that China will likely become the most influential outside power there. The continuing animosity of the Korean people toward Japan because of the abuses of the colonial period makes it unlikely that that country would become the leading player on the Peninsula. But a united Korea would be a serious midsize country in its own right and not easily dominated by any neighboring state.

Washington will likely be reluctant to make that—or any other—concession to get Beijing to adopt a more hardline policy toward Pyongyang. U.S. officials seem to assume that other countries should do what we want simply because we want it. A graphic example of that occurred in late January when Secretary of State John Kerry was on his way to Beijing to prod Chinese leaders to toughen their policy toward North Korea. On his way, he stopped to address a meeting of the Association of Southeast Asian Nations (ASEAN) to urge them to adopt a united position opposed to China’s claims in the South China Sea. The diplomatically tone-deaf secretary of state didn’t seem to grasp that Washington’s anti-China collusion with ASEAN might affect China’s willingness to take a tougher stance against North Korea.

But foreign policy is rarely a charitable enterprise. And Chinese foreign policy is never a charitable enterprise. If we want Beijing to incur the risks of getting tough with its loose cannon North Korean ally, we must offer worthwhile concessions. Unfortunately, there are no indications that our policymakers are even close to doing so.