April 19, 2025
South Korea’s political landscape has undergone a significant transformation following the Constitutional Court’s unanimous decision on April 4, 2025, to uphold the National Assembly’s impeachment of President Yoon Suk Yeol. This ruling, prompted by Yoon’s unconstitutional declaration of martial law in December 2024, has not only reshaped the nation’s governance but also introduced complex security dynamics in the region. The martial law lasted only six hours because lawmakers managed to enter the assembly building and unanimously voted to strike down his decree. This was the first time South Korea had been placed under martial law since 1980.
By removing Yoon, South Korea’s legislature exercised one of the most powerful tools in a democratic system: the ability to hold the executive accountable. Despite the unprecedented nature of Yoon’s actions—including the martial law order and crackdowns on protests—South Korea avoided violence or institutional collapse. Instead, the country turned to the rule of law.
According to the South Korean constitution, a new presidential election must be held within 60 days of the vacancy, setting the deadline for no later than June 3, 2025. The country is awaiting Acting President Han Duck-soo to announce the exact date, with indications pointing toward early June.
Yoon’s removal has elicited varied reactions from neighboring countries, each assessing how the newly elected government might influence regional stability and their strategic interests. North Korea has closely monitored developments in the South. State media reported on Yoon’s ousting, emphasizing the unanimous court decision. Analysts suggest that North Korea may see South Korea’s government transition as an opportunity to advance its military objectives. The recent unveiling of a new class of North Korean warships—capable of housing dozens of missiles—may imply this intent. These vessels, equipped with vertical launch systems, enhance North Korea’s maritime strike capabilities and could alter the strategic balance in the region.
China and Russia are also poised to capitalize on South Korea’s political change. Both nations may seek to expand their influence by exploiting any perceived weakening of the U.S.-South Korea-Japan trilateral alliance. China, in particular, might intensify efforts to sway South Korea away from U.S. influence, using economic incentives and diplomatic overtures. Russia could similarly pursue closer ties with a new South Korean government to disrupt the current security stability in the Indo-Pacific region.
The political change in Seoul brings some uncertainty to the trilateral security pact among the United States, Japan, and South Korea. This alliance is crucial for countering regional threats and needs to remain strong and stable to avoid delays or reevaluations of joint military exercises and intelligence-sharing agreements. Maintaining cohesion and trust among the three nations is imperative to deter adversaries and reassure allies during this transition period.
The impeachment and removal of President Yoon Suk Yeol mark a pivotal moment in South Korea’s democratic journey. While the nation’s institutions have demonstrated resilience, the ensuing political transition presents challenges both domestically and internationally. The upcoming presidential election and potential constitutional reforms offer avenues to fortify democratic governance. Concurrently, vigilance is required to navigate the complex security landscape, ensuring that regional adversaries do not exploit this period of uncertainty. Strengthening alliances and maintaining a unified front with key partners will be essential to uphold stability and deter opportunistic actions by neighboring states.
Tristan Witzig is a M.A. student in the International Security program with the Schar School of Policy and Government at George Mason University. He grew up in Switzerland prior to studying in the United States and holds a B.A. (honors) in History from the University of Leeds in the United Kingdom. Academic and research interests include US Foreign Policy and National Security, and how it relates to European and East Asia security. Considering a career as an analyst.