Special prosecutors had sought a 30-year term for Yoon, arguing that the drone flights were a deliberate attempt to undermine state security by fabricating an external threat. The operations, which took place in October 2024, reportedly involved the dropping of propaganda leaflets across the border. Pyongyang stated that these flights triggered a significant spike in military tensions between the two nations. In their filings, prosecutors contended that Yoon sought to use these heightened tensions as a pretext for his disastrous martial law declaration, which plunged the country into its deepest political turmoil in decades.
Yoon, who previously served as South Korea’s top prosecutor, has denied all wrongdoing in this case. His legal team has maintained that the drone operations were conducted in accordance with standard military protocols and did not constitute a criminal act aimed at subverting the state. However, the court accepted the prosecution’s argument that the timing and nature of the operations were consistent with an effort to legitimize an insurrection.
This 30-year sentence is cumulative with other convictions currently facing Yoon. In February, a South Korean court sentenced him to life in prison after finding him guilty of leading an insurrection linked to the martial law attempt. Additionally, on Monday, the Seoul Central District Court handed Yoon a two-year prison sentence for violating the country’s political funding law. In that separate case, the court found that Yoon illegally received manipulated opinion polls for free from political broker Myung Tae-kyun. Myung was sentenced to one and a half years in prison for the same charge. The court determined that Yoon had exerted undue influence on his party to support Myung’s political ambitions in exchange for access to fraudulent polling data that potentially aided Yoon in securing his party’s 2022 presidential nomination.
Yoon’s defense attorneys have indicated they will appeal the Monday ruling regarding the opinion polls, describing the evidence as insufficient. They have also appealed the February life sentence for rebellion. Last week, the country’s Supreme Court upheld a seven-year prison sentence against Yoon in a separate matter, marking the first case to reach the highest court since his ouster. Yoon was impeached by the liberal-led legislature in late 2024 after lawmakers voted to repeal the martial law order he declared late on December 3, 2024. The measure, which lasted only a few hours, was lifted after the National Assembly broke through a blockade of armed soldiers and police to vote on its repeal.
Following his formal removal by the Constitutional Court, Yoon was released from custody earlier in 2025 before being re-arrested in July to face multiple criminal trials. He has remained in detention while standing trial in seven separate cases. The recent 30-year sentence for the drone operation will likely be combined with his other sentences, though the specific mechanics of the total imprisonment period are subject to final judicial consolidation. The next major legal step involves the defense’s planned appeals against the insurrection and political funding convictions, which could ultimately alter the duration of his incarceration.
