Yoon Suk Yeol, the former president of South Korea, was sentenced to 30 years in prison by a court for sending drones into North Korea.

Yoon ordered the operation in October 2024, according to the prosecution, to annoy Pyongyang and give him an excuse for his failed martial law campaign later that year.

Yoon declared martial law on December 3, saying he was protecting the nation from “anti-state” organisations that supported North Korea. However, it soon became clear that he was driven by domestic concerns, and he changed his mind in response to strong opposition.

On Friday, the Seoul District Court found Yoon, his former defence minister Kim Yong-hyun, former chief of the Defence Counterintelligence Command Yeo In-hyung, and former head of Drone Operations Command Kim Yong-dae guilty of treason and abuse of authority.

Kim was sentenced to 30 years in prison, Yeo to 15 years, and Kim Yong-dae to three years and a five-year suspended sentence. The court ruled that the defendants utilised the pretence of a military operation to antagonise North Korea and cause an emergency.

It also noted that all three officials had “provoked North Korea,” raising the possibility of a military conflict, but concluded that Yoon bore the “greatest responsibility” in this episode.

Yoon’s lawyers said that his acts were a “legitimate” response to North Korea’s “provocations with rubbish balloons”.

This was in reference to North Korea’s 2024 release of hundreds of balloons, which were later discovered to contain “filthy waste and trash” on the South Korean border.

Since the Korean War, the two countries have used “propaganda balloons” containing slogans to promote their campaigns.

However, tensions rose in 2024 after North Korea accused the South of firing drones into its city. These drones purportedly distributed propaganda leaflets throughout Pyongyang, which the North saw as a provocation that could lead to war.

According to a judge’s decision on Friday, Yoon sent these drones into the North with the assumption that it would strike back.

Aside from the rebellion, Yoon was sentenced to five years in prison for abuse of power and hindering his own arrest.

Yoon’s effort to establish martial law, as well as the accompanying protests, sparked months of unrest in the country, culminating in an election in which Lee Jae-myung of the opposition Democratic Party won a landslide victory.