Kim Jong-il’s death on December 17, 2011 stimulated widespread expectations that sudden change might occur in North Korea as a result of political paralysis resulting from a premature father-to-son succession in North Korea. But the respective responses of both the United States and China following Kim Jong-il’s death revealed both a shared interest in preventing the outbreak of instability on the Korean peninsula and evidence of strategic mistrust over the conditions that would constitute a desirable end state on the peninsula. These responses and recent past fluctuations in Chinese policy toward North Korea and Sino-U.S. cooperation,respectively, provide a data set that can be analyzed to understand in greater detail the relationship between instability on the Korean peninsula and prospects for policy cooperation between the United States and China. This article will analyze fluctuations in Sino-American cooperation over policy toward North Korea to draw preliminary conclusions regarding the influence of the quality of Sino-American policy coordination efforts toward North Korea on both peninsular stability and Korean unification.