China's dealings with the Democratic People's Republic of Korea (DPRK) have not been easy, not even during the Korean War in which the two fought side by side. The relationship has experienced many ups and downs over the years. Most recently, the nuclear tests by North Korea and the United States' planned deployment of the Terminal High Altitude Area Defense (THAAD) system in South Korea have forced China to rethink its policy toward North Korea.This essay will analyze the recent interactions between China and the DPRK and examine the factors that prompted China to adopt a tougher stance toward Pyongyang. However, this policy change has been complicated and mitigated by the United States' decision to deploy THAAD in South Korea. Given its multiple strategic interests, China must constantly balance between different players and options, and this has put it in an awkward situation. Nevertheless, together with the United States and other UN Security Council members, China supported UN Security Council Resolution (UNSCR) 2321. Looking forward, China is also faced with the uncertainties that result from South Korea's political crisis and the transition to the Donald Trump administration in the United States.Balancing ActSince Kim Jong-il's death and his son Kim Jong-un's assumption of power in December 2011, the Sino-DPRK relationship has been lukewarm. Four years after the 18th Party Congress and Xi Jinping's rise to the Chinese Communist Party's top post, no Xi-Kim meeting has happened yet. By contrast, in that time China and the Republic of Korea (ROK) have not only exchanged state visits but also formed a free trade area, as the ROK has risen on China's foreign policy agenda.In October 2015, Liu Yunshan-one of the seven members of China's top leadership-traveled to Pyongyang for the 70th anniversary of the founding of the Worker's Party of Korea (WPK). China made an effort to improve the Sino-DPRK relationship, but less than three months later North Korea conducted its fourth nuclear test in January 2016. The test immediately changed the dynamic of relations, and two months later China and the other UN Security Council members reached a consensus and released UNSCR 2270 to impose the toughest sanctions to date against North Korea. The resolution contains unprecedented inspection and financial provisions, including mandatory inspections of cargo to and from North Korea and a requirement to terminate banking relationships with North Korean financial institutions. Most significantly, it includes for the first time sectoral sanctions, which prohibit the DPRK from both exporting key resources such as coal, gold, iron, titanium, and rare earth materials and importing aviation and rocket fuel.1With UNSCR 2270, China became much more serious with respect to implementing the Security Council resolutions concerning North Korea's nuclear and missile development activities. In early April, the Ministry of Commerce and the General Administration of Customs released a new list of embargoed items that cannot be imported from or exported to North Korea, though the list excluded items needed for maintaining the livelihood of ordinary people or providing humanitarian assistance.Pyongyang could not have been happy with the sanctions imposed by China. However, neither Beijing nor Pyongyang wanted to sever ties, and instead the two tried to maintain a normal relationship during this time of heightened tension. Shortly after the WPK had held its 7th Party Congress in May 2016-the first of its kind in more than 30 years-North Korea sent a high-level delegation to China to give a briefing on developments at the congress. The delegation was headed by Ri Su-yong, a member of the Politburo and vice chairman of the Central Committee of the WPK, who met with President Xi. The delegation delivered a message from Kim Jong-un expressing his hope to work with China to strengthen and develop the two countries' traditional bilateral friendship and, ironically, maintain peace and stability in Northeast Asia. …