China believes the US is unwilling to solve North Korean issues—militarization reinforces the narrative of the DPRK as China’s puppet—diplomacy with China shows our willingness to solve North Korean nuclear issues

Li Nan [author of letter below], "Debating North Korea: US and Chinese perspectives," Brookings, letters compiled by Susan A. Thornton, Li Nan, and Juliet Lee, 08-27-2021, https://www.brookings.edu/articles/debating-north-korea-us-and-chinese-perspectives/-- 嘉玮

China has also been frustrated with prospects for cooperation with the U.S. due to the deteriorating bilateral relationship. China believes the U.S. is not willing to solve the North Korean nuclear issue, and is thus prepared to tolerate the DPRK threat for the sake of building up its alliance against China. Washington, on the contrary, believes Beijing is not willing to address the nuclear issue because it is using Pyongyang as leverage against America and its allies. Because of these different views, plus mutual suspicion of each other’s intentions, China and the U.S. have not had any impetus to make real progress on cooperation.

China and the U.S. also have different views of the DPRK’s relationship with the other. On the one hand, the United States thinks that the DPRK is a “puppet of China.” Thus, Washington believes the only way to force Pyongyang to submit is by exerting pressure on Beijing. On the other hand, China is worried about the possibility of closer U.S.-DPRK relations for the purposes of containing China, similar to the establishment of People’s Republic of China (PRC)-U.S. diplomatic relations to contain the Soviet Union during the Cold War. Both China and the U.S. have vivid “camp thinking”—or what the Chinese like to call “Cold War thinking”—that allows the DPRK to play us off one another.