Yoon's prison sentence upheld: South Korea's Supreme Court rules

Yoon was found guilty, among other things, of excluding cabinet members from a meeting to plan martial law. The court also found him guilty of forging official documents and of obstructing investigators who wanted to arrest him.

In the first-instance proceedings in January, Yoon had been sentenced to five years in prison for obstruction of justice. An appeals court increased the sentence to seven years in April. Yoon filed a final appeal against this verdict, which has now been definitively rejected by the Supreme Court.

The three proceedings at a glance

The court's reasoning was broadcast on television. The hearing itself took place under intense public attention, as the case is seen as a litmus test for the judiciary in dealing with former heads of state.

In a separate proceeding, Yoon was sentenced to life in prison in February by a court in Seoul for "leading an insurrection." He has also filed an appeal against this verdict. In another proceeding in June, he received an additional 30 years in prison for drone flights over North Korea.

In this last proceeding, he is accused of having wanted to use the drone flights to create a pretext for the later imposition of martial law. The three proceedings together illustrate the extent of the judicial reckoning with the imposition of martial law, which lasted only hours.

Political consequences for South Korea

The Supreme Court has now rejected the appeal in the obstruction of justice case on the grounds that the lower court made "no errors." With this, the verdict in this complex is now final, while the other proceedings are still ongoing.

Political observers see the ruling as a signal that the South Korean judiciary is prepared to consistently hold even high-ranking former officeholders accountable. The decision is likely to further underscore the ongoing appeal proceedings.

Martial law had been lifted again after a few hours, after parliament voted against it. Yoon was subsequently suspended from office and later removed from his post by the Constitutional Court. The case is considered one of the deepest cuts to South Korea's democratic history since the introduction of direct presidential elections.

The Republic of South Korea has been undergoing a process of political and institutional reordering since December 2024. The now-final conviction for obstruction of justice is regarded as an initial judicial endpoint in this chapter, to which further appeal proceedings will follow.