The following is an excerpt from Sungmin Cho's op-ed in Foreign Affairs. Sungmin is a Fellow on Chinese Politics, Foreign Policy, and National Security at the Asia Society Policy Institute's Center for China Analysis.

Last month, the White House confirmed that North Korea — a country with few allies and little money — had sent thousands of soldiers to join Russia in its war against Ukraine. Pyongyang was already supplying Moscow with weapons: according to the Times of London, half of Russia’s shells used in the war have come from North Korea. But sending personnel marks a new level of coordination. There are other signs of warming ties, too. In June, Russian President Vladimir Putin made his first trip to North Korea in over two decades.

That proximity has irked China, North Korea’s main backer. Chinese officials fear that Russia’s influence over the insular dictatorship is growing at China’s expense. They also worry that the United States and its allies in Europe and Asia will strengthen military cooperation in response to Russia and North Korea’s newfound closeness. Over the past year, Beijing has chosen to react to Pyongyang’s collaboration with Moscow by publicly courting North Korea’s adversaries. For instance, in May, China held a trilateral summit with South Korea and Japan after a five-year hiatus. On the same day in June that Putin visited Pyongyang, Chinese and South Korean officials held a security dialogue in Seoul — the first such meeting in nine years.

This seeming friction between China and North Korea has tantalized many Western security analysts, who have argued that the United States and its allies should try to drive a wedge between China and North Korea. Such an effort, however, would be futile. Despite signs of tension between the two countries, North Korea is overwhelmingly reliant on China. Nearly all of its trade, for instance, is with China. The countries have not always seen eye to eye over the past 75 years, but their relationship has never come close to splintering. Instead of focusing on what could divide North Korea from China, the United States should collaborate with the Chinese government to rein in North Korea’s volatile behavior. Both the United States and China are ultimately invested in maintaining peace on the Korean Peninsula. Working together to restrain the North Korean regime is the best way to achieve it.

Read the full op-ed in Foreign Affairs.