South Korea’s former prime minister, Han Duck-soo, has been sentenced to 23 years in prison for his role in an insurrection linked to former president Yoon Suk Yeol’s failed declaration of martial law.
Judge Lee Jin-kwan ordered Han’s immediate detention following the verdict, delivered on Wednesday. Han has the right to appeal.
The ruling marks the first judicial finding that the attempted imposition of martial law on 3 December 2024 amounted to an act of insurrection.
The court found that Han had actively helped create the appearance of a legitimate cabinet meeting in order to approve an unconstitutional decree.
Prosecutors had sought a 15-year sentence, but the judge imposed a longer term, rejecting the use of sentencing precedents from past military coups.
Judge Lee described the events as a “self-coup” carried out by an elected administration, saying it posed a distinct and serious threat to democratic order.
The court said Han, as prime minister, had a constitutional obligation to prevent the attempt but instead “chose to join” it.
In sentencing, the judge said Han showed no genuine remorse, noting that he continued to conceal evidence and give false testimony throughout the trial.
Among the key pieces of evidence was a phone call on 8 December in which Han instructed a presidential aide to destroy a backdated martial law document, saying: “Let’s make it as if my signature never existed.”
The court found that Han, 76, was aware of the plan to impose martial law several hours before Yoon’s televised announcement at 10.28pm on 3 December.
CCTV footage showed Han nodding as Yoon outlined the plan and receiving documents, including the martial law proclamation.
Only six cabinet ministers were summoned in advance to the presidential office. The court ruled that Han helped ensure the meeting met the minimum quorum while preventing meaningful discussion.
Han was also found guilty of creating false documents, destroying presidential records and committing perjury during Yoon’s impeachment proceedings.
Prosecutors argued that Han bore particular responsibility because he was the only official constitutionally able to block the decree, either by refusing to countersign it or by properly convening a cabinet meeting.
Han is a career diplomat who served under five presidents from both conservative and progressive parties.
Appointed prime minister by Yoon in May 2022, he became the longest-serving prime minister under a single president in South Korea’s democratic history.
Throughout the trial, Han maintained that he privately opposed the declaration of martial law and acted under psychological shock.
“I never supported it or tried to help it,” he told the court in November.
Unlike Yoon and several other defendants, Han had remained at liberty during his trial after a judge rejected a request for his arrest in August, citing legal uncertainty over his culpability.
The verdict comes five days after another court sentenced Yoon to five years in prison for obstructing his own arrest.
Yoon’s separate verdict on charges of insurrection is due on 19 February. Prosecutors are seeking the death penalty.
