SEOUL — A Seoul court on Friday sentenced former President Yoon Suk Yeol to 30 years in prison after finding him guilty of abuse of power and violating military command protocols, for ordering the clandestine deployment of armed drones into North Korean airspace in a covert operation that resulted in civilian casualties on both sides of the border.
The case marks the first time a sitting or former South Korean president has been held criminally accountable for actions taken during a North Korea-related military operation, and sets a precedent that legal scholars say could reshape the constitutional boundaries of presidential war powers in the country.
Prosecutors had demanded a 35-year sentence, arguing that Yoon authorized the drone flights without cabinet approval or notification to the National Assembly, bypassing legal channels in what the court described as a “deliberate and sustained pattern of concealment.” The defence team announced it would appeal, calling the verdict “politically motivated.”
The operation, carried out in early 2025 during Yoon’s final months in office, involved at least four Unmanned Aerial Vehicles loaded with surveillance equipment and at least two armed variants programmed to target suspected weapons facilities near the North Korean border city of Kaesong. One drone strayed off course and crashed in a populated area, killing a civilian maintenance worker and injuring three others, according to a UN fact-finding mission.
North Korea responded with artillery salvos that damaged infrastructure in the border province of Gyeonggi, and Pyongyang’s state media described the drone operation as an “act of war.” The incident brought the two Koreas to the edge of a broader conflict at a moment when diplomatic channels had been showing tentative signs of progress.
Yoon, who was arrested in January 2026 after unsuccessfully attempting to flee the country, has remained in custody since his transfer to the Seoul Detention Centre. His legal team argued the drones were conducting routine reconnaissance under a standing presidential directive and that civilian casualties resulted from equipment malfunction, not deliberate targeting — a claim the court rejected after reviewing flight logs and internal communications recovered from the presidential archives.
The verdict drew immediate reaction from across the political spectrum. Acting President and Prime Minister Han Duck-soo said the government “respects the court’s decision” and called for national unity, while the main opposition Democratic Party called it “a watershed moment for democratic accountability in Korea.” The ruling People Power Party condemned the sentence as “disproportionate.”
Regional analysts warned the case could complicate deterrence calculations on the peninsula at a time when North Korea has accelerated its missile testing programme and deepened its military cooperation with Russia. “The last thing anyone needs right now is a political vacuum in the South while Pyongyang is probing for weaknesses,” said Dr. Ji Hye-won, a security analyst at the Korea Institute for National Unification.
Yoon is the third former South Korean president to face criminal prosecution in recent decades, following the convictions of Lee Myung-bak and Park Geun-hye on corruption charges. The court’s ruling is subject to automatic appeal and is not expected to take effect until higher courts rule on the case.
Kenji Tanaka
Kenji Tanaka covers Asia Pacific security, technology, and geopolitics from Tokyo.