South Korean President Yoon Suk-yeol speaks during the final hearing of his impeachment trial on February 25, 2025, in Seoul. (©Constitutional Court of Korea, Yonhap/Kyodo)
On December 3, 2024, then-South Korean President Yoon Suk-yeol declared emergency martial law, vowing to "eradicate anti-state forces" and restore what he described as political normalcy.
Within hours, troops moved into central Seoul and toward the National Assembly and several other state institutions. Images and video streams of that day were instantly broadcast live around the world. By the early hours of December 4, however, parliament voted to revoke the decree, and Yoon rescinded it shortly thereafter.
The entire episode lasted roughly six hours.
The event was, for sure, shocking, destabilizing, and ultimately ruled unconstitutional by South Korea's Constitutional Court. But the criminal charge subsequently brought against the former president — spearheading an insurrection — demands a far higher legal threshold than political recklessness or even misuse of power.
Yoon has already been convicted in a related case. On January 16, 2026, he was sentenced to five years in prison for abuse of power, obstruction of justice, and falsifying official documents. And today, February 19, 2026, the trial court is expected to rule on the broader insurrection charge, which carries the gravest penalties under Korean law: death or life imprisonment.
Whatever one thinks of Yoon or his stint in office, the question before the court is not whether martial law was justified. It is whether prosecutors have proved, beyond a reasonable doubt, that the president attempted to overthrow the constitutional order by force.
And on that narrower legal question, the case is far less clear than the political narrative suggests.
Was It Subversion of the State
South Korea's Criminal Code defines insurrection as the collective use of force to usurp national territory or subvert the Constitution. Historically, the provision has been applied to classic coup scenarios like sustained military mobilization, seizure of territory or government facilities, and suppression of civilian authority.
The December 3 episode does not fit comfortably within that tradition. Martial law forces were dispatched, but no territory was seized, no rival authority installed, and no lasting suspension of civilian governance occurred. Parliament convened a few hours later to vote against the decree and prevailed. The president complied. Civil administration across the country continued uninterrupted.
These facts alone may not render the decision lawful. But criminal insurrection requires more than illegality. It requires an overthrow or attempted overthrow of the constitutional order. The prosecution's burden is therefore not merely to show that Yoon misused emergency powers, but that he intended and operationalized a coup against a constitutional organ of the state.
That burden is extraordinarily high. And it is not obvious that it has been clearly met.
Intent Matters, and Is Ambiguous Here
Insurrection is likewise an intentional crime. Courts must infer purpose from conduct. Prosecutors argue that deploying troops to the legislature and to other institutions reveals intent to disable them. Yet the operational reality complicates that inference.
If the objective had been to neutralize the National Assembly or other governmental facilities, the president-controlled forces would have been capable of doing so decisively.
Broadcasting, communication lines, utilities, and transportation would have been shut down immediately. Access routes could have been completely sealed. None of these measures was implemented – at least not to a degree one would expect from a "properly" executed martial law.
Most tellingly, the decree lasted only hours. Yoon rescinded it after the parliament voted to undo the order. A leader attempting to overthrow constitutional order would not typically terminate his own seizure of power at the first institutional pushback.
The prosecution is correct that even a failed or aborted coup can constitute insurrection. But the shorter, less coercive, and more reversible the episode, the harder it becomes to establish intent beyond a reasonable doubt.
Key Evidence Contested
Further weakening the prosecution's case is the presence of heavily contested evidence. Notably, Kim Hyun‑tae, former commander of the elite 707th Special Mission Group, initially testified that Yoon's orders had aimed to blockade the National Assembly.
In subsequent court testimony, he clarified that the orders were intended to guard against external threats, not to subdue lawmakers in the parliament.
Similarly, the widely discussed memos by Hong Jang‑won, former First Deputy Director of the National Intelligence Service, were presented during proceedings as suggesting coordinated coercion. Their credibility and evidentiary value, however, were sharply disputed.
Cross-examinations revealed inconsistencies regarding the memos' origin and content, leading defense lawyers to argue that they could not be taken as definitive proof of premeditated planning for an insurrection or targeting of Yoon's political opponents.
Scale and Force Were Limited
As mentioned earlier, insurrection jurisprudence in South Korea has largely involved sustained violent mobilization, including occupation of cities, prolonged suppression of institutions, or armed clashes.
The December 3 deployment, while alarming, was nonviolent and limited in scope and time. No shots were fired. No civilian authority was displaced. Government ministries functioned normally nationwide.
South Korean courts have held that insurrection may be committed through the organized use of state forces to subvert the constitutional order, not only through popular uprising. That position reflects the realities of modern constitutional governance, where threats can arise from within state institutions as well as from mass revolt.
Yet recognizing that possibility does not eliminate the need to preserve meaningful legal boundaries. If any ill-judged deployment of troops around state organs is deemed insurrectionary, the concept risks expanding beyond its traditional core — violent attempts to overthrow the constitutional order — into the broader and less precise terrain of emergency misgovernance or political misjudgement.
Criminal law traditionally resists such expansion precisely because insurrection carries the gravest penalties in the code.
Gridlock and Motive
Although the exact rationale for Yoon's decision that day remains unclear, it's worth noting that martial law came amid extraordinary gridlock.
Yoon governed under an opposition-controlled National Assembly that repeatedly blocked key appointments, budgets, and initiatives. Impeachment motions against senior officials proliferated. Street protests headed by left-wing groups calling for his ouster began very early in his term. South Korea's polarized media environment amplified confrontation.
In South Korea, where the president lacks the kind of executive authority seen in the United States, an opposition-led parliament can effectively stymie almost any initiative. Ironically, though, some of conservative Yoon's policies, including rapprochement with Japan and an expanded nuclear energy agenda, once heavily criticized, are now being pursued by the left-leaning incumbent with minimal resistance.
Of course, none of this may justify martial law. But it contextualizes motive. The defense's claim — that Yoon acted in a perceived constitutional emergency rather than revolutionary intent — is not implausible on its face.
Democratic systems regularly experience severe executive-legislative standoffs. Leaders sometimes overreach disastrously in response. But those standoffs do not automatically constitute insurrection.
The Risk of Doctrinal Overreach
Courts in related cases involving subordinate officials have already characterized the December 3 martial law as an insurrection. That creates momentum toward a similar conclusion for the ex-president. The question, however, should be whether the event itself met statutory elements. Leadership liability should then follow. If the classification remains contestable, leadership conviction becomes correspondingly unsupportable.
This matters because orchestrating an insurrection in South Korea is punishable by death or life imprisonment. Such penalties demand exceptional evidentiary clarity. Legal systems reserve them for unmistakable assaults on the state.
Stretching it to cover brief, reversible emergency measures would turn a coup provision into a general sanction against executive overreach. That shift would not strengthen constitutionalism. It would blur the boundary between political accountability and criminal rebellion.
The impeachment already removed Yoon from office. He's been subjected to months of intensive investigation while in detention and convicted on related, lesser charges. Criminal law should intervene only if the higher threshold of violent subversion is unmistakably crossed.
Otherwise, constitutional crises risk becoming crimes by definition — a precedent future governments of any ideology may inherit.
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Author: Kenji Yoshida
