Political Turmoil in South Korea: Crisis, Politics, and Implications

The martial law crisis revealed both the strength of South Korea’s institutions and the fragility of its democracy.

South Korea is facing one of its gravest political crises since democratisation in 1987. On 12 November, former Prime Minister Hwang Kyo-ahn was arrested for allegedly inciting insurrection related to last year’s declaration of martial law by President Yoon Suk Yeol. His arrest is a key moment in a probe that has already led to senior detentions and Yoon’s impeachment and removal.

Man at the centre

Hwang Kyo-ahn is a major figure in South Korean politics. He served as Prime Minister from 2015 to 2017 under President Park Geun-hye and briefly as Acting President after her impeachment in 2016. Before entering politics, he spent three decades as a prosecutor, gaining both prominence and controversy.The path to his arrest began on 3 December 2024. That night, President Yoon Suk Yeol shocked the country by declaring an emergency martial law. He accused the opposition-controlled National Assembly of being an “anti-state den of criminals” aligned with North Korea. He claimed the decree was needed to protect democracy. Yoon deployed armed soldiers to the Assembly. He reportedly ordered the arrest of opposition leaders and even members of his own party.The response was swift and unexpected. Legislators rushed to parliament and bypassed military barricades. They unanimously revoked the order within hours. Mass protests erupted nationwide. Opposition parties immediately launched impeachment proceedings. Within days, the National Assembly impeached Yoon and suspended his powers. The Constitutional Court upheld the move and permanently removed him from office.

During this period, Hwang posted messages supporting Yoon’s martial law declaration. He urged a crackdown on “pro-North leftist forces”. Prosecutors say these statements incited insurrection and endorsed actions that violated constitutional norms. After ignoring multiple summonses from the special counsel, Hwang was detained and arrested last week.

Political reactions

Hwang’s arrest is part of a broader probe into officials tied to the attempted power grab. Former National Intelligence Service Director Cho Tae-yong was also arrested, accused of failing to report Yoon’s illegal martial law plan, as well as perjury, destroying evidence, and falsifying documents. He is the eighth NIS chief to be arrested since the agency’s founding, highlighting long-standing concerns about politicisation and abuse of power in the security services.The legal process has been deeply divisive. Soon after Hwang’s detention, a court rejected the arrest warrant, citing insufficient evidence.Reactions remain sharply split: opposition lawmakers and civil society groups demand accountability for all involved, while conservative politicians and commentators dismiss the probe as a political “witch hunt”.

Democracy Under Stress

The martial law crisis exposed both the strength and fragility of South Korea’s democracy.Swift action by lawmakers, mass protests, and interventions by the National Assembly and Constitutional Court showed resilient institutions and strong public commitment to constitutional rule.But the crisis also exposed weaknesses: the presidency concentrates significant power, and critics say weak checks and balances—combined with a single five-year term—allow room for abuse. With this now the second impeachment in under a decade, calls for constitutional reforms to curb executive power are growing.Deep political polarisation is another concern. Politics has become increasingly fragmented, with parties prioritising loyalty over compromise. Impeachment motions and presidential vetoes surged during Yoon’s brief tenure, signalling eroding institutional restraint. This polarisation undermines cooperation and threatens democratic stability.The intelligence and security services also raise alarms. The former NIS director’s arrest underscores fear of politicisation within institutions meant to remain neutral and the risks when security agencies serve partisan rather than national interests.

Regional, global ramifications

South Korea’s political turmoil also has regional repercussions. North Korea has shown unusual restraint, limiting its commentary to domestic media and avoiding efforts to exploit the crisis.The United States has voiced confidence in South Korea’s institutions while avoiding direct criticism of Yoon to preserve alliance stability. China has also been cautious despite earlier anti-China rhetoric, likely calculating that non-interference serves its interests. Japan has issued careful statements, worried about the impact on trilateral security cooperation with Seoul and Washington.Economically, the crisis has shaken investor confidence. Analysts warn that prolonged instability could weaken South Korea’s credit rating and slow growth. With the global economy strained by trade tensions, the leaderless impeachment period has left the country poorly positioned to manage rising pressures.South Korea’s experience underscores the need for swift institutional pushback against authoritarian overreach, the risks of concentrated executive power, and the difficulty of sustaining pro-democracy coalitions amid deep partisan divides.President Lee Jae-myung must now rebuild public trust, manage economic pressures, and navigate a complex foreign-policy landscape. At home, calls to curb presidential power and strengthen checks and balances are growing, though consensus remains unlikely amid entrenched political divisions.

The stakes for South Korea's democracy remain high.

(The writer is a foreign affairs expert. Views personal.)