The Martial Law Declaration That Sparked a Constitutional Crisis

The crisis began on December 3, 2024, when President Yoon Suk Yeol made a shocking late-night televised address declaring martial law across South Korea. This marked the first time such measures had been imposed since the military dictatorship of Chun Doo-hwan in 1980. In his speech, Yoon claimed the action was necessary to protect the nation from what he called anti-state forces and accused opposition lawmakers of sympathizing with North Korea while paralyzing government operations through repeated impeachment motions against his officials.

The martial law decree immediately banned all political activities, placed media under military control, and gave sweeping powers to Army General Park An-su, whom Yoon appointed as martial law commander. Special forces troops were deployed to the National Assembly building, with dramatic scenes showing soldiers attempting to prevent lawmakers from entering the chamber. Videos circulated widely showing legislators climbing over fences and pushing past military personnel to reach the assembly hall.

Within hours of the declaration, massive crowds of South Korean citizens took to the streets in spontaneous protests, viewing the martial law order as an attempted coup. The National Assembly convened an emergency session despite the military presence, with lawmakers from both ruling and opposition parties voting unanimously to nullify the martial law decree. The vote passed with all 190 legislators present supporting the motion to overturn Yoon’s order.

Faced with overwhelming public opposition and the parliamentary vote, President Yoon reversed his martial law declaration just six hours after announcing it. However, the damage to his presidency proved irreversible. The opposition Democratic Party immediately filed impeachment proceedings, citing Yoon’s actions as a fundamental violation of democratic principles and constitutional law. The failed martial law attempt exposed deep political divisions within South Korea and raised serious questions about presidential power and accountability.

The Impeachment Process and Legal Proceedings

The first impeachment motion against President Yoon was introduced to the National Assembly on December 7, 2024, just four days after the martial law incident. However, this initial attempt failed to reach the required quorum when members of Yoon’s ruling People Power Party boycotted the vote, preventing the two-thirds majority needed for presidential impeachment under South Korean constitutional law. The failure of this first motion demonstrated the deep partisan divisions within the National Assembly and sparked further public outcry.

Following the failed first vote, opposition lawmakers vowed to continue pursuing impeachment on a weekly basis. Public pressure intensified as millions of South Koreans participated in candlelight vigils and street demonstrations demanding Yoon’s removal. Opinion polls showed that a clear majority of citizens believed the president should either resign voluntarily or face formal removal through impeachment. The political crisis deepened as several of Yoon’s key officials, including Defense Minister Kim Yong-hyun, resigned or faced their own impeachment proceedings.

The second impeachment motion came to a vote on December 14, 2024. This time, political dynamics had shifted significantly. Several members of the ruling People Power Party broke ranks and participated in the vote, with party leader Han Dong-hoon encouraging lawmakers to vote according to their conscience rather than party loyalty. The impeachment bill passed with 204 of 300 National Assembly members voting in favor, surpassing the required two-thirds majority and immediately suspending Yoon from his presidential duties.

With Yoon suspended, Prime Minister Han Duck-soo assumed the role of acting president while the Constitutional Court reviewed the impeachment case. The court was required by law to reach a decision within 180 days. During this period, the case generated intense national attention, with both pro-Yoon and anti-Yoon protesters holding massive weekly demonstrations in Seoul and other major cities. The political uncertainty created challenges for governance and raised concerns about South Korea’s stability as a key United States ally in East Asia.

Constitutional Court Findings and Legal Violations

The Constitutional Court conducted extensive hearings and deliberations before reaching its verdict. The case centered on five major allegations against President Yoon, each representing serious violations of South Korean constitutional law and democratic principles. The court’s investigation examined evidence including military deployment orders, communications between government officials, and testimony from key witnesses involved in the martial law declaration.

The court found that President Yoon illegally declared martial law without meeting the constitutional requirements for such emergency measures. Article 77 of the South Korean Constitution permits martial law only in cases of military necessity or to maintain public safety during national emergencies. The justices determined that no such emergency existed on December 3, 2024, and that political disagreements with the opposition-controlled National Assembly did not constitute grounds for military intervention.

The second major violation involved Yoon’s order to deploy military forces to block lawmakers from entering the National Assembly. The court established that even during lawful martial law, there is no legal basis for preventing the legislature from convening or impeding its activities. The deployment of special forces to the assembly building represented an unconstitutional attempt to prevent elected representatives from exercising their legislative duties, including their power to overturn martial law declarations.

Additional illegal acts included attempts to arrest Supreme Court justices and other judicial officials, which violated the separation of powers enshrined in the constitution. The court also found evidence that Yoon ordered raids on the National Election Commission, raising concerns about potential interference with democratic institutions. Furthermore, investigators discovered planning documents that suggested possible plans to provoke incidents with North Korea to justify the martial law, allegations that military officials strongly denied.

Acting Chief Justice Moon Hyung-bae emphasized that President Yoon had abandoned his responsibility to safeguard the constitution and gravely betrayed public trust. The ruling stated that by declaring martial law, Yoon created chaos across South Korean society, economy, and foreign policy. The court rejected Yoon’s defense that martial law was a legitimate tool to address parliamentary gridlock, stating that political disputes must be resolved through democratic processes rather than military force.

National Celebrations and Public Response

The Constitutional Court’s announcement sparked immediate and widespread celebrations across South Korea. Millions of citizens who had spent months protesting and demanding accountability erupted in jubilation when the unanimous verdict was announced. In downtown Seoul, crowds gathered near the Constitutional Court building and at major public squares, waving flags, chanting pro-democracy slogans, and celebrating what they viewed as a victory for democratic principles and the rule of law.

The celebrations reflected the deep emotional investment that South Korean citizens had in the outcome of the impeachment case. Many protesters had participated in weekly demonstrations for over four months, maintaining constant pressure on political institutions to uphold constitutional principles. The gatherings featured music performances, speeches by democracy activists, and collective expressions of relief that the constitutional crisis had been resolved through legal processes rather than violence or continued political deadlock.

Opposition leader Lee Jae-myung, who heads the Democratic Party and is considered a leading candidate in the upcoming presidential election, addressed supporters and characterized the ruling as the beginning of a true democratic South Korea. He emphasized that the decision demonstrated the sovereignty of the people and their ability to hold leaders accountable through constitutional mechanisms. Lee praised the millions of citizens who participated in peaceful protests and called for national unity moving forward.

The Korean Confederation of Trade Unions issued a statement welcoming Yoon’s removal and declaring that after 123 days, the attempted coup had finally ended. Labor organizations had played significant roles in organizing protests and mobilizing workers to participate in demonstrations. The confederation emphasized that while removing Yoon represented an important victory, the struggle for democracy would continue and required ongoing vigilance to protect constitutional governance and workers’ rights.

However, the national mood was far from unanimous. Outside Yoon’s official residence and in certain conservative neighborhoods, his supporters gathered in somber protests, expressing anger and disappointment at the verdict. These demonstrations, though smaller than the pro-impeachment rallies, represented a significant minority of South Koreans who viewed Yoon as a victim of partisan politics and believed the impeachment was legally flawed. Some protesters questioned the legitimacy of the process and called for continued resistance to the court’s decision.

The deep polarization revealed by these contrasting reactions highlighted the challenges facing South Korea as it moves forward. Political scientists noted that the divisions exposed by the martial law crisis and subsequent impeachment reflected broader societal tensions around questions of governance, the role of the presidency, and the balance between different political ideologies. Some analysts compared the polarization to political divides in other democracies, including comparisons between Yoon’s supporters and certain populist movements in Western countries.

Political Aftermath and Government Transition

Following the Constitutional Court’s decision, the South Korean government immediately began implementing the constitutional procedures required for presidential succession. The presidential flag was lowered at Yoon’s office in Yongsan, Seoul, symbolizing the formal end of his presidency. Yoon’s chief of staff, national security adviser, and thirteen other senior aides submitted their resignations to acting President Han Duck-soo, though Han rejected most of these resignations, citing the need to maintain stable government operations during the transition period.

Acting President Han Duck-soo delivered a televised address following the verdict, pledging to ensure national security and diplomatic stability while overseeing a smooth transition to the next elected president. Han announced that the presidential election would be held on June 3, 2025, exactly sixty days after the court’s ruling as required by the constitution. He emphasized his commitment to managing the election process fairly and maintaining regular government functions until the new president takes office.

The People Power Party, Yoon’s conservative political party, issued a statement accepting the court’s decision with what officials described as gravity and humility. Party leaders acknowledged that respecting the verdict was essential to upholding democracy and the rule of law. However, the party faces significant challenges heading into the snap election, as polling data suggests that public opinion has turned sharply against the conservative movement following the martial law crisis and impeachment.

On April 11, 2025, one week after the ruling, Yoon and his wife vacated the presidential residence and returned to their personal home in the Gangnam district of Seoul. In a written statement responding to his removal, Yoon expressed regret and apologized for failing to meet public expectations. He thanked his supporters and stated that it had been an honor to serve as president, though he made no specific reference to the martial law declaration or the circumstances leading to his impeachment.

Criminal Proceedings and Legal Consequences

The Constitutional Court ruling represents only one aspect of the legal consequences facing the former president. Yoon faces separate criminal proceedings on charges of insurrection, rebellion, and abuse of power related to his martial law declaration. These criminal charges carry severe potential penalties under South Korean law, including the possibility of life imprisonment or even the death penalty, though South Korea has not carried out executions in decades.

Yoon became the first sitting South Korean president to face an arrest warrant when prosecutors obtained authorization to detain him in January 2025. After initially evading arrest for several days and taking refuge in the presidential compound, he was eventually taken into custody on January 15, 2025, becoming the first sitting president in South Korean history to be arrested and incarcerated. He spent nearly two months in detention before a Seoul district court granted him release in March, citing procedural issues with his arrest, though the criminal charges against him remain active.

The criminal trial formally began on April 14, 2025, just ten days after the Constitutional Court’s impeachment ruling. Prosecutors have assembled extensive evidence including recordings of military communications, deployment orders, planning documents, and testimony from officials who participated in or witnessed the martial law preparations. The prosecution argues that Yoon’s actions constituted an attempted insurrection against the constitutional order and represent one of the most serious abuses of presidential power in South Korean democratic history.

Defense attorneys for the former president have argued that martial law was a legitimate presidential prerogative under the constitution and that Yoon intended only to issue a warning to opposition lawmakers whom he believed were paralyzing government operations. They contend that he always planned to respect the National Assembly’s authority to overturn the decree and that no actual coup attempt occurred. However, legal experts widely rejected these arguments, noting that the deployment of military forces to prevent legislative activity contradicts claims of respecting parliamentary authority.

Beyond Yoon himself, several high-ranking officials face their own criminal investigations and potential prosecution. Former Defense Minister Kim Yong-hyun was arrested in December 2024 on suspicion of committing insurrection by advising Yoon to declare martial law and ordering troops to seize control of the National Assembly. Other military commanders and government officials who participated in planning or implementing the martial law decree have been questioned by prosecutors and may face charges depending on the evidence gathered during the ongoing investigation.

Historical Context and Democratic Implications

The removal of President Yoon Suk Yeol marks the second time in less than a decade that South Korea has impeached and removed a sitting president. The previous case involved Park Geun-hye, who was impeached in 2016 and removed from office by a unanimous Constitutional Court decision in 2017 following a corruption scandal. Park subsequently served several years in prison before receiving a controversial presidential pardon. The fact that two consecutive conservative presidents have been impeached and removed has prompted serious reflection within South Korean society about political accountability and the health of democratic institutions.

South Korea’s modern democratic era began with the adoption of its current constitution in 1987, which established the framework for direct presidential elections and limited executive power following decades of authoritarian military rule. The constitution deliberately made presidential impeachment difficult, requiring a two-thirds legislative majority, to ensure stability while still providing mechanisms for removing leaders who seriously violate the law or constitution. The successful impeachment and removal of two presidents demonstrates that these constitutional safeguards function as intended when political will and public pressure align.

However, the ease with which presidents can declare martial law under the current constitution has emerged as a significant concern. The 1987 constitution was drafted during a period when memories of military dictatorship remained fresh, yet it still grants presidents considerable emergency powers. The recent crisis has prompted calls for constitutional reform to place additional checks on presidential authority, particularly regarding martial law declarations, deployment of military forces domestically, and other emergency powers that could be abused to undermine democratic processes.

International observers praised South Korea’s handling of the constitutional crisis, noting that democratic institutions ultimately prevailed despite the serious threat posed by the martial law attempt. The rapid response of the National Assembly in overturning the decree, the persistent citizen protests demanding accountability, and the thorough judicial review by the Constitutional Court all demonstrated the resilience of South Korean democracy. However, analysts also expressed concern about the deep political polarization revealed by the crisis and the challenges this poses for governance and social cohesion moving forward.

Impact on Foreign Relations and National Security

The political crisis surrounding President Yoon’s impeachment occurred during a particularly sensitive period for South Korean foreign relations and national security. Yoon had positioned himself as a staunchly pro-United States leader who strengthened security cooperation with Washington and pursued improved relations with Japan despite domestic opposition. His removal from office came just as Donald Trump prepared to return to the United States presidency, creating uncertainty about continuity in the bilateral relationship and security cooperation.

The timing proved especially problematic given escalating tensions with North Korea and China’s growing assertiveness in the region. South Korea plays a crucial role in United States security strategy for East Asia, hosting tens of thousands of American troops and serving as a key ally in deterring North Korean aggression. The months of political uncertainty and leadership vacuum created by the impeachment crisis raised concerns in Washington about South Korea’s ability to respond effectively to regional security challenges and maintain its commitments to the alliance.

Yoon’s approach to North Korea had been notably harder-line compared to his predecessor, emphasizing deterrence and refusing to engage in dialogue without preconditions. He strengthened military cooperation with the United States and Japan, including through the historic Camp David summit in 2023 that elevated trilateral security coordination to unprecedented levels. His removal potentially opens the door for a shift in policy, particularly if opposition leader Lee Jae-myung wins the upcoming presidential election, as Lee’s Democratic Party has historically favored engagement and dialogue with Pyongyang.

Relations with Japan also face uncertainty following Yoon’s removal. Despite low domestic approval ratings, Yoon had prioritized improving ties with Tokyo, meeting with Japanese Prime Minister Kishida Fumio twelve times during his presidency. This represented a dramatic shift from the tensions that characterized Korea-Japan relations during previous administrations. Whether the next president will maintain this warming trend or respond to domestic sentiment favoring a tougher stance toward Japan remains an open question with significant implications for regional stability and United States alliance management.

Economic considerations add another layer of complexity to the transition. South Korea faces new tariffs imposed by the Trump administration on exports to the United States, creating pressure for trade negotiations at a time when the acting government has limited political capital and legitimacy to make major policy commitments. Business leaders and economic analysts expressed concern that the prolonged political uncertainty could harm investment, consumer confidence, and South Korea’s reputation as a stable and reliable economic partner in global markets.

The Road to Presidential Election

With the Constitutional Court’s ruling finalizing Yoon’s removal, South Korea enters a compressed campaign period leading to the June 3, 2025 presidential election. The short timeframe of sixty days contrasts sharply with normal presidential elections, which typically involve campaigns lasting many months. Political parties must quickly select candidates, develop platforms, and mobilize voters under intense time pressure while the nation remains deeply divided over the impeachment and its implications.

Opposition leader Lee Jae-myung enters the race as the clear frontrunner according to opinion polls. Lee narrowly lost to Yoon in the 2022 presidential election by less than one percentage point, one of the closest margins in South Korean history. Since then, he has consolidated his position as leader of the Democratic Party and maintained high visibility through his role in leading the impeachment efforts. His campaign is expected to emphasize economic justice, engagement with North Korea, and restoring what he characterizes as democratic norms damaged during Yoon’s presidency.

However, Lee faces his own controversies and legal challenges. He was convicted in 2024 on election law violations that would have barred him from running for office, but an appeals court overturned that conviction in April 2025, just days before the Constitutional Court’s impeachment ruling. He still faces other pending legal cases that could potentially affect his candidacy or presidency if elected. Despite these issues, his supporters view him as a champion of progressive values and social equality who can heal the divisions created by Yoon’s presidency.

The conservative People Power Party faces a difficult path to victory given the backlash against Yoon and questions about the party’s judgment in supporting him even after the martial law declaration. The party must quickly select a candidate who can distance themselves from Yoon’s actions while still appealing to the conservative base that supported the former president. Several potential candidates have emerged, but none command the same level of name recognition or organizational support as Lee Jae-myung, and opinion polls show conservatives trailing significantly.

Voter turnout and enthusiasm will play crucial roles in determining the outcome. The intense public engagement during the impeachment crisis suggests high participation is likely, which typically benefits opposition parties in South Korean politics. However, the conservative base remains energized despite Yoon’s removal, and unexpected developments during the short campaign period could shift the dynamics. International factors including trade negotiations with the United States and security developments involving North Korea could also influence voter preferences and priorities.

Conclusion

The unanimous Constitutional Court decision removing President Yoon Suk Yeol from office represents a watershed moment in South Korean democracy. The ruling affirmed that no leader stands above the law and that the constitution provides effective mechanisms for holding presidents accountable when they violate democratic principles. The months of citizen protests, legislative action, and judicial review demonstrated the strength and resilience of South Korea’s democratic institutions even when facing a serious constitutional crisis.

However, the celebration of Yoon’s removal must be tempered by recognition of the deep challenges facing South Korean society. The political polarization revealed by the crisis has not disappeared with the court’s verdict, and the nation remains sharply divided over questions of governance, ideology, and national direction. Healing these divisions will require leadership that prioritizes national unity and democratic values over partisan advantage, a difficult task in any political system but especially challenging given the compressed timeline before the upcoming election.

The case also highlights broader questions about presidential power and constitutional design that South Korea must address. The relative ease with which Yoon declared martial law, despite the absence of genuine emergency conditions, suggests that constitutional reforms may be necessary to prevent future abuses. Strengthening checks on presidential authority, clarifying the conditions for emergency powers, and enhancing mechanisms for early intervention when leaders show authoritarian tendencies should be priorities for whoever assumes the presidency after the June election.

As South Korea moves forward, the international community will watch closely to see how this mature democracy navigates its transition to new leadership. The peaceful resolution of the constitutional crisis through legal and political institutions rather than violence stands as a testament to South Korea’s democratic development. However, the true test will come in the months and years ahead as the nation works to bridge its divisions, address the underlying political and social tensions that the crisis exposed, and chart a course that upholds democratic values while effectively addressing the security and economic challenges facing the country. The removal of President Yoon marks not an ending but rather the beginning of a critical period that will shape South Korean democracy for years to come.