In April 2025, South Korea’s Constitutional Court unanimously confirmed the impeachment of President Yoon Suk-yeol, officially removing him from office after he attempted to impose martial law on December 3, 2024—the first such incident in the history of the Sixth Republic. After declaring martial law, Yoon had ordered military troops and tanks to surround the National Assembly, forbidding any entry. In an act of defiance, members of parliament climbed over the fences and forced their way inside, managing to pass a resolution to rescind the declaration and impeach the president ten days later.

To understand the weight of these events, we need to look back at South Korea’s democratic journey. The last time martial law was declared was under military dictator Chun Doo-hwan, who used it to suppress the Gwangju Uprising in 1980. His reign—the last dictatorial regime—lasted until 1987, when following mass anti-government protests, South Korea held its first democratic elections, ushering in the Sixth Republic (Kurbanov, 2009: 344). That same year, a referendum adopted a new constitution that limited the powers of the president, strengthened the National Assembly, and established the Constitutional Court, a body that oversees democracy and the rule of law (Kurbanov, 2009: 342-343).

Since then, the Constitutional Court has become a crucial body for resolving disputes not only about laws but also about the limits of political power. For example, it has handled several high-profile impeachment cases: in 2004, the court reinstated President Roh Moo-hyun; in 2017, it upheld the removal of President Park Geun-hye; and now, once again, it is playing a decisive role in the removal of Yoon Suk-yeol. Just how fast night changes—South Korea’s first former prosecutor to become president, Yoon Suk-yeol, is now a former president too.

In the history of the Sixth Republic, the prosecution often played the role of informal opposition force—especially toward the end of presidential terms, when it launched corruption investigations against outgoing leaders and their inner circles. This helped build the image of the prosecution as an independent institution, standing for law and order and, to some extent, existing outside the traditional political sphere. Despite this reputation, however, the prosecutor’s office has traditionally maintained a conservative formalism in its work.  In recent years, it is associated less with the “power of the people” and more with judicial power. This shift became especially clear with the rise of Yoon Suk-yeol, as the political system began to tilt noticeably in favor of the prosecution. For the first time in South Korea’s history, in 2022, a prosecutor-president came to power, so the structure that had previously served as a tool to contain the government found itself at the center of the this political system.

Yoon Suk-yeol entered politics at a time when public trust in politicians in power was falling sharply. Scandals during the previous presidency, a growing number of social conflicts, dissatisfaction with the Democratic Party’s decisions, as well as a worsening economy created a favorable ground for an “anti-system” candidate. In this context, the former Prosecutor General looked like a fresh start—not connected to any party machine, but with a strong image as a fighter against corruption and, more importantly, against the corruption of the ruling Democratic Party.

President Yoon, as a former law enforcement officer, knows well that prosecutors can only launch an investigation when there’s a formal request or evidence, as well as clear legal basis for their action. This last point is crucial, as prosecutorial work is, above all, about upholding the legal framework. The situation in South Korea is further complicated by the fact that prosecutors hold near-total control over investigations, meaning the ultimate decision to initiate or suspend an investigation lies solely with them. This isn’t just about possible abuse of power — it’s a deeper problem in the system. Things may look legal on the surface, but in reality, this weakens the rule of law and gives too much power to one group.

Today, according to political scientist Nancy Bermeo, democratic backsliding, or democratic erosion, happens through hidden but formally and legally justified steps to weaken democratic procedures from within—instead of through aggressive, rapid changes. Everything also looks legitimate, but step by step key institutions and democratic processes are falling into disrepair.

In South Korea, a key mechanism has been the redistribution of personnel within the law enforcement and political systems. Yoon began his presidency with large-scale purges and appointments: key positions in the prosecution, ministries, state agencies, and the presidential office were given to the president’s relatives, former colleagues, friends, or even media personas who had openly spoken out against the Democratic Party. In several cases, the appointments looked like a direct transfer of power to close allies, including those who were often criticized for lacking administrative experience. A clear pattern stands out: Yoon systematically strengthened control over institutions related to executive, investigating, and defense functions: the prosecution, security services, and internal safety agencies. After all, such institutions are most often used as tools for public pressure and political control. This strategy reflects a classic pattern of democratic erosion—the concentration of power in loyal hands under the facade of legitimacy.

In Bermeo’s work on democratic backsliding, a more precise term is used to describe such processes – executive aggrandizement. This is a form of democratic erosion in which an elected leader gradually and legally weakens autonomous institutions, restricts space for the opposition and civil society, and systematically reshapes the power structure to fit their interests. The main point of this process is that the executive branch itself loses its autonomy and internal balance, turning into a centralized mechanism.

In South Korea, the concentration of executive power in the hands of a single person quickly led to other institutional consequences. Civil servants, opposition politicians – including Lee Jae-myung, Yoon Suk-yeol’s main rival in the last election, and journalists from major broadcasting networks such as Newstapa and MBC, all of whom spoke out against the president’s actions, came under constant pressure from the prosecution. Investigations against them were launched quickly, and legal justifications were found instantly, while cases involving Yoon’s inner circle – including his wife and allies—were either delayed or saw no progress at all. Selective law enforcement not only became the norm—it now seems embedded into the very structure of state governance, serving as a tool to suppress any form of dissent.

The culmination of Yoon Suk-yeol’s presidency was, paradoxically, an attempt at a classic coup – the so-called “executive coup,” which, as noted by Nancy Bermeo, has become an extremely rare occurrence in the 21st century. On December 3, 2024, President Yoon, under the pretext of a “threat against the state” declared martial law, ordered the blockade of the National Assembly, and commanded the seizure of key documents from the National Election Commission.

The official justification for declaring martial law was the parliamentary majority held by the Democratic Party, which, according to the president, was creating a “legislative dictatorship.” It had been clear for a long time that President Yoon Suk-yeol faced serious difficulties working with the current government. Over two years, he vetoed parliamentary decisions 15 times — the highest number in South Korean history. At the same time, the Democratic Party made 22 attempts to initiate impeachment proceedings against government officials. All this only emphasises the complete impossibility of dialogue between the executive and legislative branches.

Given this history, the declaration of martial law was clearly part of a long-term strategy to accuse the opposition of election fraud and challenge the Democratic Party’s recent victory—effectively removing political rivals from the game. After all, President Yoon—a former prosecutor—built his entire political rhetoric around fighting corruption, the Democratic Party, and what he described as “corruption of the Democratic Party.”

Nevertheless, the attempt failed—within just a few hours, protests broke out in the streets, while the parliament and opposition responded quickly and decisively. Martial law was revoked, and within a little bit more than a week, the president was impeached. Whatever President Yoon’s intentions may have been, South Korean society—despite clear signs of democratic erosion in recent years—demonstrated the resilience of its institutional mechanisms and a strong unwillingness to accept violent autocratic methods, which they had already stood up against back in 1987.

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