Case Studies | The Return of Trump’s Diplomacy: Kim Jong Un and the United Nations Security Council
Samantha Lu and Freddie Mallinson
For North Korea, 2025 has been off to a busy start. On January 20, 2025, President Trump was sworn in as the 47th president of the United States, and North Korea conducted three missile tests throughout the month, a notable spike compared to the usual frequency. North Korea’s January missile tests sent a clear message to the new administration: Pyongyang will not back down from its nuclear posturing.
The Situation on the Korean Peninsula
As Trump’s second term begins, he faces a drastically different North Korea than when he left office four years ago. Pyongyang has not only expanded its nuclear arsenal but also deepened its military ties with Moscow. This includes the ratification of a mutual defense treaty and the deployment of North Korean troops to the Russo-Ukraine war — the first time North Korean troops have seen large-scale active combat since 1953. Along with other changes, some experts assess these developments have likely emboldened Kim Jong Un to believe he now holds more leverage vis-a-vis the Trump Administration
The political turmoil in South Korea further fuels uncertainty about the future of U.S.-North Korea relations. On December 3, 2024, then-President Yoon Suk Yeol declared martial law for the first time since 1987. Yoon’s declaration was met with massive protests, and the National Assembly unanimously voted to overturn the declaration. A few hours later, Yoon reversed his declaration and ended martial law. However, turmoil within the political system continued as Yoon and his subsequent acting president were impeached later that month. Another destabilizing factor on the peninsula is that Kim may be tempted to take advantage of South Korea’s leadership crisis as a window of opportunity to act boldly. As the future of South Korea’s leadership remains uncertain, it is challenging to determine how Trump will engage. In his first term, Trump described his relationship with then-President Moon Jae-in as “very, very close.” Depending on who the next South Korean president is, what U.S.-South Korea relations will look like in the next four years remains to be seen.
Trump’s Tactics
During the first Trump administration, both leaders enjoyed far warmer ties than previous U.S. and North Korean leaders. In 2018, they held a U.S.-North Korea leader summit in Singapore, the first-ever meeting between a U.S. and North Korean leader. Following this meeting, Trump announced he would halt U.S. “war games” with South Korea to facilitate denuclearization talks.
South Korea is one of the closest U.S. allies in the Indo-Pacific and has a combined forces command with the United States. As a result, Trump’s decision to suspend military exercises was met with shock. A year later, in 2019, Trump and Kim met again. This time, they held talks at the Korean Demilitarized Zone before Trump briefly entered North Korea, making him only the third U.S. president to do so after Presidents Clinton and Carter.
Trump’s approach to North Korea was markedly different from the longstanding U.S. approach. For years, the United States has strictly sanctioned North Korea, pressuring it to give up its nuclear weapons program. This has primarily occurred through United Nations Security Council (UNSC) resolutions. In a recent ISD case study, A Tale of Two Vetoes: How North Korea Tests the UN System — and the Great Powers, ISD Senior State Department Fellow Christopher Klein details how the UNSC has shifted away from consistently voting to sanction North Korea following missile tests as China and Russia have increasingly used the UNSC to pursue their own agendas. As a career diplomat who has served as the Political Minister-Counselor to the U.S. Mission to the United Nations from 2013 to 2017, Klein draws from his own experiences to provide insights into the significance of these changing UNSC voting patterns.
UNSC on North Korea
In 2006, North Korea conducted its first nuclear test. In response, the UNSC quickly imposed a round of sanctions against Pyongyang. As North Korea continued its missile tests in subsequent years, the UNSC imposed increasingly stricter sanctions. Between 2006 and 2022, all five permanent members (P5) unanimously adopted resolutions that sanctioned North Korea. However, this came to a halt in May 2022 when Russia and China voted against a resolution on North Korea, marking the first vetoes on a North Korea-related resolution in more than six decades.
Two months prior, in March 2022, North Korea had successfully tested an intercontinental ballistic missile (ICBM) for the first time in four years, clearly violating previous UNSC resolutions and sanctions. Yet, on that occasion, Russia and China were unwilling to adopt new resolutions that would have enacted further sanctions. Klein explains that there was little new left to sanction after nearly two decades of UNSC resolutions that sanctioned North Korea. This became a sticking point for China and Russia who regarded additional sanctions as ineffective and having “no relevance to settling the nuclear issue on the peninsula.”
The historic UN vetoes also occurred amid worsening U.S.-China relations and stronger China-Russia relations, which have further divided the UNSC. Klein reveals that before 2022, the United States and China held private negotiations to develop draft resolutions — to which China agreed — before bringing the resolution to the floor for an official vote. However, as U.S.-China relations degraded, so did these negotiations, limiting the United States’ ability to bring China on board with its resolutions.
Since the 2022 vetoes, China and Russia have blocked all subsequent resolutions on North Korea. In an attempt to rein in the P5 from using vetoes to support their internal agendas, Liechtenstein pushed forward an important UN General Assembly reform that required P5 members who cast a veto to explain their rationale. Despite this, Klein recounts, the P5 members remain undeterred to cast vetoes.
Entering the second Trump term, it is unclear what role the United States will play in the UN. Trump’s nominee for U.S. Ambassador to the UN, Elsie Stefanik has vowed to hold an “America First” approach in the UN, including potentially reducing budget contributions if the UN runs counter to U.S. interests. It will also be critical to watch and see if rising tensions between the United States, China, and Russia continue to play out within the UNSC or if the United States will increasingly leverage its interests through the UN.
Regardless of Stefanik’s approach to the UN, Trump’s personal relationships with counterparts will continue to play a prominent role in U.S. foreign policy. It will be important to watch how interactions between Trump, Kim, and the future South Korean leader play out, as this will likely have an outsized impact on the security dynamics of the Korean Peninsula.
Samantha Lu is a research assistant at the Institute for the Study of Diplomacy and a graduate student in the Asian Studies Program at the Walsh School of Foreign Service concentrating in politics and security.
Freddie Mallinson is the assistant director of programs and research at the Institute for the Study of Diplomacy. He has a M.A. in Security Studies from the Walsh School of Foreign Service with a concentration in U.S. national security policy.
Interested in learning more about North Korea’s nuclear program or the role of the United Nations in negotiations? Check out Christopher Klein’s case study and others in ISD’s in-depth case studies library and join the faculty lounge to access free instructor copies:
