South Korea shocked the world on Dec. 3, 2024, when then-President Yoon Suk Yeol declared martial law and deployed military forces to take over the National Assembly. The troops were blocked by lawmakers and citizens who barricaded the building’s entrances. The unprecedented turmoil was brought under control in the following days. South Korea proved its democratic resilience through its judicial process and democratic institutions. Korea’s legal system responded to the crisis in stages. First, within two and a half hours of Yoon’s declaration of martial law, the National Assembly passed a resolution demanding its lifting. Then, on April 4, 2025, the Constitutional Court determined in the impeachment case that the president’s declaration of martial law, including the deployment of military and police forces to the National Assembly, constituted grave violations of the Constitution and the law, and removed Yoon from office. Subsequently, on Feb. 19, 2026, the criminal trial court convicted the former president of insurrection and sentenced him to life imprisonment.
More than a matter of political conflict, the episode was a test of whether the separation of powers and the democratic safeguards embedded in the country’s constitution would function in a moment of crisis. The principal issues addressed in the first-instance criminal judgment offer a compelling case study of how the South Korean judicial system served as a bulwark of democratic resilience in the face of a crisis. It should be made clear, however, that the judgment is not yet final, and that appellate proceedings are currently underway following appeals by both the defendant and the prosecution.
Insurrection and Criminal Responsibility
What the trial court regarded as central to the criminal conduct was not simply the president’s verbal declaration of martial law itself, but a series of concrete acts carried out with the aim of substantially paralyzing the functions of the National Assembly for a considerable period by sending troops there. These acts included the blockade of the National Assembly, attempts to arrest major political figures, and attempts to secure control of the National Election Commission. The court held that the deployment of armed military personnel to the National Assembly, the resulting physical clashes, and the mobilization of equipment and vehicles for arrests were themselves sufficient to satisfy the “riot” element of the crime of insurrection. In other words, the absence of prolonged armed conflict or large-scale bloodshed did not preclude the establishment of insurrection.
During the trial, Yoon argued that the repeated impeachment attempts by the opposition-controlled National Assembly and sweeping budget cuts had rendered the government impossible to run, and that the declaration of martial law was not a means of seizing power but an unavoidable emergency measure intended to break a prolonged state of governmental paralysis. Paradoxically, that argument raises a broader question as to whether Korea’s constitutional system contains adequate mechanisms to defuse or mediate extreme conflict between the legislative and executive branches before it escalates. The court, however, held that problems between the two branches of government must be resolved strictly through the procedures contemplated by the Constitution and laws, and cannot be addressed by using force to block the exercise of authority by constitutional institutions. Ultimately, the court treated as decisive not the president’s political motives or sense of crisis as such, but whether his conduct crossed constitutional limits and moved toward altering the legal order by force.
Two legal holdings of particular importance emerged from the judgment. First, even a president may be the subject of the crime of insurrection. The court reasoned that the purpose of subverting the constitutional order includes not only the formal abolition of constitutional institutions, but also rendering them unable to exercise their powers for a substantial period. Accordingly, the fact that martial law is a constitutionally recognized power does not itself provide immunity. If martial law was used as a means of infringing the essential functions of the National Assembly, then it was not a constitutionally contemplated exercise of power but a destruction of the constitutional order by force. Second, because insurrection is a collective offense, the leader may bear responsibility for the entirety of the enterprise even if he did not personally direct every individual act of execution or participate in every scene, so long as he led the overall plan and implementation under a common purpose.
The criminal judgments against related actors reinforce this point. In the same trial, former Minister of National Defense Kim Yong-hyun was sentenced to 30 years’ imprisonment; former Defense Intelligence Commander Noh Sang-won to 18 years; former Commissioner General of the Korean National Police Agency Cho Ji-ho to 12 years; former Seoul Metropolitan Police Commissioner Kim Bong-sik to 10 years; and former head of the National Assembly Security Guard Mok Hyun-tae to three years. By contrast, Kim Yong-gun, a retired colonel and former commander in the military police, and Yoon Seung-young, Chief of Investigation Planning and Coordination at the National Police Agency, were acquitted on the ground that there was insufficient evidence to establish that they recognized and agreed to the purpose of subverting the constitutional order. This shows that the court did not simply emphasize the gravity of the incident in the abstract, but individually examined whether each defendant had in fact shared the unconstitutional objective.
In sentencing, the court combined symbolism with specificity. It began from the premise that insurrection is an offense of danger that inherently carries an exceptionally high degree of risk because it threatens the very existence of the state and its constitutional functions. The court further observed that the acts in this case damaged the political neutrality of the military and police, diminished Korea’s standing and international credibility, drove society into extreme polarization, and imposed enormous social costs. As for Yoon personally, the court treated as aggravating factors that he had led the offense, involved numerous others in its execution, failed to apologize for the consequences, and even refused to appear during parts of the proceedings. At the same time, the court took into account that the plan could not be regarded as highly sophisticated, that there had been efforts to restrain the possession of live ammunition and the use of direct physical force, and that Yoon had no prior criminal record and had served in public office for many years. For those reasons, the court-imposed life imprisonment rather than the death penalty.
Democratic Resilience and Constitutional Vulnerability
This judgment should be understood from the perspective of how a democratic state articulates legal responsibility for the abuse of power by the head of the executive branch. In this case, the Korean judiciary did not attempt to resolve the underlying political controversy itself. Rather, it examined as a legal matter whether the attempt to suspend the functions of the legislature and arrest political figures through the mobilization of military and police power constituted a destruction of the constitutional order, and to what extent responsibility for that conduct could be attributed to an individual. In that sense, the judgment may be read not as an example of the judicialization of politics, but as an instance in which the judiciary served as the final brake against the exercise of raw power outside the Constitution.
At the same time, the judgment also exposes the vulnerabilities of Korea’s constitutional system. The court noted that in advanced democracies it is rare for a president, after reaching an extreme conflict with the legislature, to mobilize the military, precisely because those systems have more refined mechanisms to prevent such conflict from escalating to that stage. This suggests that while Korea ultimately managed to control the crisis after the fact, it lacked sufficient institutional devices to alleviate conflict between the legislative and executive branches at an earlier stage. In the end, the judgment demonstrates both that the courts functioned as the last safeguard of constitutional democracy and that there remains a pressing need for institutional buffers capable of operating before a crisis reaches the point where that final safeguard must be invoked.
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The views expressed in this article are solely those of the author and do not represent the official position of the Korean judiciary.
