Sung-Yoon Lee () is a South Korean political scientist, author, and commentator on Korean studies and East Asian studies, specializing in North Korea, who has been active mainly in the United States.
He is the Principal Fellow in the Center for Korean Peninsula Strategy at the Sejong Institute, a private South Korean foreign policy and security think tank. Previously, he was a fellow at the Woodrow Wilson International Center for Scholars and Kim Koo-Korea Foundation Professor in Korean Studies and assistant professor at the Fletcher School of Law and Diplomacy, Tufts University. He was also an associate in research at the Korea Institute, Harvard University, and a research fellow at the National Asia Research Program.
In June 2023, Lee published his first book, The Sister: North Korea's Kim Yo Jong, the Most Dangerous Woman in the World, profiling Kim Yo-jong, the sibling of, and closest aide to, Kim Jong Un, North Korea's leader.
Lee has provided advice to the US government and is an outspoken proponent of several policies aimed at changing the North Korean regime towards a path of denuclearization and improvement of human rights, while keeping the peace and stability in Northeast Asia. Lee has argued that this can be accomplished with a dual strategy of stern treatment of the North Korean government through unwavering economic sanctions aimed at weakening the leadership and security apparatus, while engaging the country's people through information campaigns that break their isolation from the outside world, humanitarian aid, and a global campaign of human rights.
He has also stated that the US and its military presence in Northeast Asia have brought decades of stability and prosperity to the region, and supports its continued stationing in the Korean peninsula. He also encourages the eventual unification of Korea under the South's direction, with the active support of the US and China, and a resulting united country that is amicable to both powers.
He is a prominent advocate of hard-line, sanctions-centered policies toward North Korea. Lee has been a longstanding critic of engagement-oriented approaches such as the Sunshine Policy. He has also been a persistent critic of South Korea's progressive administrations, arguing that the governments of Kim Dae-jung, Roh Moo-hyun and Moon Jae-in did not deliver substantive improvements in press freedom or restraint in the use of state power, and describing South Korea as having undergone democratic backsliding under Moon.
Early life and education
Lee was born in Seoul, South Korea. In part due to his father being a South Korean diplomat, Lee spent part of his youth in England, Switzerland, and the US.
Lee majored in American and British literature at New College in Sarasota, Florida, graduating in 1991. He pursued his graduate studies at the Fletcher School, completing his Master of Arts in 1994, and his Ph.D. in 1998. John Curtis Perry became his doctoral advisor and developed a lifelong mentor-mentee relationship. In his dissertation "The antinomy of divine right and the right to resistance: tianming, dei gratia, and vox populi in Syngman Rhee's Korea, 1945–1960", Lee analyzed the interplay between Confucianism and democracy in defining political authority and statecraft during the early years of the Republic of Korea.
Career
Upon completing his PhD, Lee joined the faculty of The Fletcher School of Law and Diplomacy as the adjunct assistant professor of international politics in 1998 and until 2005. Concurrently he was also the visiting assistant professor of history at Tufts University starting in 2000 and until 2005. Between 2005 and 2006 he was the Kim Koo Research Associate at the Korea Institute, Harvard University. In 2007 he resumed his position at the Fletcher School, and in 2012 became the first holder of the newly created chair Kim Koo-Korea Foundation Assistant Professor of Korean Studies. He held that position until 2023, afterwards becoming a fellow at the Woodrow Wilson International Center for Scholars for one year. In 2025 he joined the Korean think tank Sejong Institute's Center for Korean Peninsula Strategy, as a Principal Fellow.
He has taught International Relations of the United States and East Asia 1945 to Present, United States and East Asia, Politics of the Korean Peninsula: Foreign and Inter-Korean Relations, and North Korean State and Society.
Lee has also been an adjunct assistant professor of Asian studies at Bowdoin College in 2000, and the visiting professor of Korean studies at Sogang University in 2007, and at Seoul National University from 2012 to 2016.
From 1999 until 2013 Lee was an associate in research at the Korea Institute, Harvard University. There he launched a new seminar series, the "Kim Koo Forum on U.S.-Korea Relations", in 2005. He is a former research fellow with the National Asia Research Program, a joint initiative by the National Bureau of Asian Research and the Woodrow Wilson International Center for Scholars. Lee has attended numerous conferences as a speaker, moderator and interpreter. He is also a frequent commentator on Korean affairs on radio, television and print, with The Guardian calling him "among the most insightful and prescient chroniclers" on the behavior of North Korea's regime. Lee has also testified in the United States Congress to provide expert advice on North Korea policy issues.
Since 2013 Lee has been advising the U.S. government on legislation and other executive action against the North Korean regime, including strengthening US sanctions. He has advised both the US President and legislators, including participating in Congressional hearings for the House Foreign Affairs Committee and Senate Foreign Relations Committee.
He has frequently contributed to media outlets, also making there a case for sanctions.
These efforts contributed towards a bill, passed in 2016, of unprecedented tough sanctions primarily aimed at restricting cash flows into the country in an effort to undermine its nuclear warhead and long-range missile development, and constrict Pyongyang's ability to pay (and retain the loyalty of) its party elites, security forces, and military.
In 2018 Lee participated in the Warmbier v. DPRK trial in Washington D.C. as an expert witness for the plaintiffs. The judge ruled against the DPRK, in the torture, hostage taking, and extrajudicial killing of Otto Warmbier.
Policy views on North Korea
Lee argues that the actions the regime takes both internationally and against its own people “are calculated and predicable, not random and crazy,” and he is known for using the application of historical patterns to understand and predict future conditions in North Korea.
Lee has advocated for a strategy of stern treatment of the North Korean government, while engaging the North Korean people. That includes economic pressure aimed at the elite, especially targeting its palace economy that depends on illicit activities including proliferation, smuggling, counterfeiting, and money laundering. It also means availing substantial humanitarian aid, provided it reaches the intended recipients, increasing efforts to disseminate more information from the outside world into North Korea, facilitating defections, and pressing for a global campaign of human rights.
Lee has underscored that the only non-military way to force North Korea into a real negotiation on denuclearization and human rights is to exert sustained economic and propaganda pressure to "destroy the Kim regime’s instruments of self-preservation": A nuclear program, a loyal ruling class, and a submissive society. That is, by on the one hand pushing more outside information into the North so its society can turn against the regime, and on the other hand by exerting sanctions that limit the cash used to prop the military and ruling apparatus, the regime would weaken to the point of near-collapse, forcing it to negotiate a transition, including a pragmatic way out for the Kim family.
Lee has frequently urged policymakers not to fall for the "self-defeating" trap of short-term concessionary diplomacy; patronizingly thinking that the regime can be persuaded through diplomacy and appeasement. Instead he urges taking the long view of an unwavering strategy of pressure. Lee sustains that refraining from making concessions in exchange for North Korea halting its cyclical belligerence is the most effective way to deter future provocations.
Achieving denuclearization and regime change Financial and trade sanctions Lee emphatically has asserted that "the only nonmilitary means of forestalling [North Korea's nuclear and missile developments] is for the US to enforce both American and United Nations sanctions against the North Korean regime and its enablers, the foremost of which remains China."
Sanctions should be primarily imposed (as some have) by the U.N. Security Council, and therefore make them binding on the entire international community. However, these "so far did little damage to Pyongyang’s economy thanks to Beijing’s massive material support through the backdoor," further, Beijing has demonstrated "a disingenuous pattern of diplomatic ambidexterity. China has made token gestures like signing on to UN Security Council resolutions while failing to enforce them fully"
Sanctions are the means to reduce external inflows of cash that the regime needs to advance its nuclear and missile development, as well as to keep its ruling class and security apparatus loyal. These sanctions, if made strong and sustained in time, would lead to significantly weakening the regime to the point of near-collapse; by prompting "bankruptcy and the consequent destabilization" and the "specter of revolt or regime collapse", South Korea and the US could negotiate from a position of strength a peaceful transition of the regime that would include real denuclearization and improvement of human rights, as well as a pragmatic "way out for the Kims."
Lee has concluded that a key point of leverage are American-led financial sanctions, since the regime deeply relies on dollars as its foreign currency, and the US is uniquely positioned to use its control over the dollar-based international financial system as well as its economic might, to more effectively impose and enforce sanctions. Overall, Lee recommends:
Direct sanctions on North Korea's international trade and financial flows. Block any trade of arms, luxury goods, and other goods or services that are a significant source of cash or material support to the regime. Freeze the assets of Kim Jong Un or any of his top deputies, who are believed to have billions of dollars in European and Chinese banks. Secondary sanctions: Impose sanctions on North Korea's partners, "thus presenting them with a strong economic disincentive: Either continue to do business with North Korea and be blocked out of the U.S. financial system or stop all business with North Korea and continue to have access to the U.S. financial system," Publicly identify and sanction all foreign companies, financial institutions, and governments assisting North Korea's nuclear and missile programs. This crucially includes "levying hefty fines on the Chinese banks that, unwittingly or otherwise, launder money for Pyongyang and facilitate dollar transactions on behalf of North Korean entities."
As a reference point on strength and duration of sanctions, Lee remarks that it took several years for a combination of direct and secondary sanctions to bring Iran back to the bargaining table. Moreover, contrary to popular belief, sanctions on North Korea are not "maxed out"; rather, until the sanctions imposed by the US in 2016, American sanctions against North Korea were much weaker than those applied to Iran, Syria, or Burma, Belarus, and Zimbabwe. The 2016 US sanctions brought the enforcement against the North to a "normal" level.
Avoiding concessionary diplomacy