Yoon’s December Gamble: Martial Law, Impeachment, and Geopolitical Effects
Dr. Anudeep Gujjeti
The recent political turmoil in South Korea, marked by President Yoon Suk Yeol’s declaration of martial law and subsequent impeachment, has raised profound questions about the stability of the nation’s democratic institutions and its geopolitical trajectory. This issue closely represents a correlation between domestics politics and the foreign policy decision making of leaders which in turn has the potential to throw regional security policies into disarray.
On December 3rd, President Yoon Suk Yeol declared a state of emergency and imposed martial law, citing what he described as “ant-state, pro-North Korean forces” attempting to undermine South Korea’s liberal democratic institutions. The proclamation threatened the curtailing of civil liberties, banning political activities, demonstrations, and free speech while granting sweeping powers to law enforcement and military authorities. Yoon justified these measures by claiming the National Assembly’s actions were equal to legislative dictatorship and treason, threatening to drive the nation into civil unrest. This unprecedented move, the first since 1980, shocked South Korean society and drew immediate backlash from across the political spectrum. Even members of Yoon’s People’s Power Party (PPP) expressed reservations about the drastic measure, while opposition parties and civil society groups labelled the declaration an assault on democracy.
The martial law declaration was met with swift and intense opposition. By early December 4th, the South Korean National Assembly convened an emergency session, during which 190 of its 300 members voted to demand the immediate revocation of martial law. This unanimous opposition, including dissenting voices from within Yoon’s own party, forced the president to withdraw the declaration within hours. Public outrage, coupled with mass protests, further underscored the unpopularity of Yoon’s decision, with many drawing parallels to the situation to South Korea’s authoritarian past. The swift reversal did very little to assuage the calls for Yoon’s resignation or impeachment. He was accused of undermining democratic norms and abusing his executive authority and eroding public trust in his leadership.
The political fallout from the martial law debacle culminated in impeachment proceedings against President Yoon. On December 14th, the National Assembly voted decisively to impeach him, with 204 lawmakers, including 12 from the PPP, supporting the motion. This marked only the second time in South Korea’s history that a sitting president was impeached. Earlier to Yoon’s impeachment, the former Defence Minister of South Korea was arrested. The vote immediately suspended Yoon from office, with Prime Minister Han Duck-soo assuming the role of acting president.
The impeachment now moved to the Constitutional Court which must decide whether to uphold the decision. Although the court has up to 180 days to rule, public pressure and the urgency of the situation might bring a quick resolution. Six of the nine justices must vote in favour for the impeachment to take its final course. Looking at the public outrage the court’s decision will be heavily influenced by public sentiment, which has overwhelmingly turned against Yoon with his approval ratings plummeting to historic low.
If the Constitutional Court upholds Yoon’s impeachment, South Korea must hold a presidential election within 60 days of the impeachment. The opposition Democratic Party (DP), led by Lee Jae-myung, is well positioned to capitalize on the crisis. Lee Jae, who narrowly lost to Yoon in the 2022 presidential election, has been a vocal critic of Yoon’s policies, in general to his approach to foreign relations and domestic governance and in particular to Japan and United States (US).
The DP’s leader emphasises greater autonomy in South Korea’s foreign policy, advocating for a balanced approach to managing relations with both the US and China. Lee has also expressed scepticism toward Yoon’s efforts to strengthen ties with Japan, criticizing agreements related to historical grievances, such as wartime forced labour, as “humiliating” considering the colonial rule of Japan over South Korea during 1910-1945.
Yoon’s presidency has been marked by a concerted effort to pivot South Korea’s foreign policy closer to the US and Japan. His administration worked to mend historical tensions with Japan, culminating in a summit with then-Prime Minister Fumio Kishida in 2023. This rapprochement, encouraged by Washington, aimed to bolster trilateral cooperation against shared security threats, including North Korea’s nuclear ambitions and China’s growing influence. The martial law crisis and Yoon’s removal threaten to unravel these fragile diplomatic achievements. A new administration under Lee Jae-myung would likely take a more critical stance toward Japan, even revisiting the agreements made under Yoon. This could strain the fragile partnership between South Korea and Japan with broader implications for the US led regional security initiatives in the Northeast Asia as well as the Indo-Pacific.
Lee’s calls for a less adversarial relationship with China which further complicates the issue. While maintaining the US-South Korea alliance remains a cornerstone of South Korea’s foreign policy, a shift toward greater economic cooperation with China could introduce friction with the US. The US, which has long sought to strengthen the trilateral alliance with South Korea and Japan, may find itself navigating a more complex and uncertain dynamic. Ironically, the US is the only treaty ally of the South Korea and has around 28,500 US troops stationed South Korea, for which both the nations have agreed for a cost sharing model in October 2024. An unstable South Korean administration especially coinciding with Trump taking over the US Presidency on January 20, who is very transactional in nature, even complicates the dynamics.
Domestically, Yoon’s impeachment has reignited debates about the structure of South Korea’s political system. Critics argue that the concentration of power in the presidency has made the office prone to abuse, as evidenced by the tumultuous tenures of recent leaders. Regionally, the upheaval raises concerns about the continuity of South Korea’s foreign policy and its role in maintaining stability in Northeast Asia. The US and Japan, both of which have invested in closer ties with South Korea, especially after the “trilateral Camp David agreement”, are closely monitoring the situation. Prime Minister of Japan Shigeru Ishiba and the US Secretary of State Antony Blinken have expressed hope for a peaceful resolution but acknowledged the potential for disruption.
The uncertainty surrounding South Korea’s leadership comes at a critical juncture, with challenges such as North Korea’s nuclear program, China’s assertiveness, Trump 2.0 and the need for economic resilience demanding steady and effective governance. A prolonged political vacuum or a significant shift in policy direction would weaken South Korea’s position in the region and undermine collective efforts to address regional security challenges.
Dr. Anudeep Gujjeti is Assistant Professor at the Center of Excellence for Geopolitics and International Studies, REVA University, Bengaluru.
