Who planted the ill-advised idea of martial law in President Yoon Suk Yeol’s mind?

As of noon Wednesday, roughly 8 hours after military rule was officially dropped following a parliamentary motion to revoke it, Defense Minister Kim Yong-hyun appears to have been the key figure.

The Defense Ministry confirmed Wednesday that Kim, who assumed his role in September this year, had proposed the declaration of emergency martial law to the president through the prime minister. By law, either the defense or interior minister can propose martial law to the president via the prime minister in times of national emergency.

Kim, a few minutes before the presidential decree went into effect at 11 p.m. Tuesday, called a meeting of key commanders and ordered heightened vigilance across the military.

As lawmakers gathered to invoke parliament's power to overturn the decree, armed forces, including members of the Army’s special operations unit, entered the National Assembly’s main building, where the voting session was scheduled to take place.

Kim, 66, is a former three-star Army general and an alumnus of the president’s high school, joined Yoon’s presidential campaign team in 2022. He is said to have played a leading role in relocating the presidential office to the Ministry of National Defense building in Yongsan and was later appointed as director of the Presidential Security Service.

When he was appointed defense minister in August this year, some opposition lawmakers raised suspicions that his appointment was part of a plot by Yoon’s office involving a martial law decree.

On Tuesday, this concern proved to be true.

Kim is also from what is now infamously known as the "Chungam faction," a group within the president’s inner circle composed of alumni from Chungam High School in Eunpyeong-gu, Seoul. Kim graduated from the school one year before the president.

Another key member is Lee Sang-min, the interior minister, who graduated four years after Yoon.

Yoon has kept Lee as his interior minister despite calls for his removal following the Itaewon crowd crush in October 2022.

The "Chungam faction," and their supposed role in the martial law declaration, has drawn parallels with the secret military group "Hanahoe" in the 1970s, which was a key vehicle for military general-turned-dictator Chun Doo-hwan to seize power through a coup in 1979. It also consisted mainly of alumni from the 11th class of the Korea Military Academy, including Chun and his long-time friend and successor, President Roh Tae-woo.