Revelations from a controversial notebook has exposed what appears to be a chilling blueprint for impeached South Korean President Yoon Suk-yeol’s martial law declaration, outlining extensive plans for mass arrests of opposition leaders, judges and civil society leaders — and potentially even extrajudicial killings.

Attributed to former army intelligence commander Noh Sang-won, believed to be a central figure in Yoon’s martial law plans, the notes have sparked alarm over the extent of the current administration’s authoritarian tendencies. 

The implications of these revelations seem to extend beyond Noh’s alleged personal musings, as additional evidence suggests a broader network of officials involved in discussions surrounding martial law.

Experts told Korea Pro that the emergence of such extreme measures signals an unsettling revival of South Korea’s authoritarian past, with disturbing parallels to the military rule of Park Chung-hee and Chun Doo-hwan.

While legal and political hurdles complicate efforts to verify the authenticity of Noh’s notebook, the broader concern remains the erosion of democratic norms in South Korea. With public trust in government institutions at stake, experts stressed the need for clear accountability and a return to political restraint among Seoul’s leaders.  

The situation underscores a sobering reality — even the most stable democracies remain vulnerable to the specter of authoritarianism, and how South Korea responds now may define its political trajectory for years to come.

Main opposition Democratic Party leader Lee Jae-myung stands with senior party lawmakers at the National Assembly, Dec. 7, 2024 | Image: Democratic Party of Korea

TAKING EXTREME MEASURES

The latest revelations arising from Noh’s notebook paint a vivid picture of a detailed martial law plot that was seemingly willing to take things to extremes, including categorized lists of potential arrest targets and methods for detaining — and even killing — political opponents.

According to an exclusive from public broadcaster MBC, the notebook divided arrest targets into alphabetical categories from A to D, with “Grade A” targets including former President Moon Jae-in, Democratic Party leader Lee Jae-myung and other prominent opposition politicians.

However, the detention plan was not simply limited to politicians, as the notebook also listed religious leaders, judges and left-leaning civil society figures such as former soccer star Cha Bum-kun.

After arrest, the prisoners would then be transported to sites including the northwestern Yeonpyeong Island and southwestern Jeju Island, but most concerningly, Noh’s notes reportedly suggested the possibility of “accidents during transport.”

The notebook also contained terms like “gas,” “explosion,” “sinking” and “sinking by gunfire,” as well as a more specific implementation plan outlining the locations and killing methods such as grenades.

Bizarrely, Noh reportedly planned to seek North Korea’s help in covering up the “executions” by sending the bodies “straight to the North” for disposal, despite the notebook also outlining a plot to induce an inter-Korean maritime conflict as a pretext for martial law.

Choi Gi-il, a professor at Sangji University’s National Security Division, described the entire affair as “undeniably shocking” and like “something out of a Hollywood movie.”

He told Korea Pro that if Noh indeed contacted North Korea, his actions would constitute “high treason” and mean that South Korean citizens were essentially used as “leverage for certain political purposes.”

Doubts remain about whether Noh’s notes were part of the actual martial law plot or simply his personal thoughts, but Choi said his extreme plans nonetheless suggest a “deeply entrenched delusional mindset.”

Meanwhile, former National Intelligence Service (NIS) deputy director Hong Jang-won recently revealed a memo containing a list of political targets he was allegedly ordered to arrest, including Lee Jae-myung, National Assembly Speaker Woo Won-shik and former ruling People Power Party leader Han Dong-hoon.

However, NIS chief Cho Tae-yong has disputed his former deputy’s claims, while Hong himself altered part of his testimony during a follow-up hearing, citing a “slight error” in his memory.

The questions about the authenticity of Hong’s memo and Noh’s “fragmented” notes and their relation to the actual martial law imposition present obstacles for the prosecution to use them as evidence.

In Noh’s case, the situation is compounded by an inconclusive handwriting analysis result, and his refusal to testify so far has made it harder for authorities to authenticate the notebook.

Despite these legal hurdles, the notebook and memo could undermine President Yoon’s argument that the martial law declaration was simply intended as a “warning” to his “anti-state” opponents after what he claims to be rigged parliamentary elections last April.

From left: Then-South Korean President Chun Doo-hwan at the ROK Army’s II Corps in 1983, then-South Korean President Park Chung-hee pours ceremonial champagne during an opening ceremony of the Gyeongin and Gyeongbu Expressways in 1968 | Image: ROK National Archives, edited by Korea Pro

BRINGING BACK AN AUTHORITARIAN PAST

Experts have expressed deep concern to Korea Pro that former army intelligence commander Noh’s alleged martial law plans and Yoon Suk-yeol’s past rhetoric bear striking similarities to tactics adopted by South Korea’s military dictators.

Noh’s notebook reportedly detailed plans for constitutional changes to permit three-term presidencies and designate successors for Yoon, echoing tactics used by former President Park Chung-hee.

The former intelligence commander’s succession planning notes further drew parallels to dictator Chun Doo-hwan, who also rose to power in a 1979 military coup. After student activist Park Jong-chul died from police torture in Jan. 1987, Chun banned electoral reform discussions through his Protection of the Constitution decree (호헌조치), announcing he would appoint his successor and pass on his presidential powers.

Choi of Sangji University expressed shock over Yoon’s reference to “anti-state forces” during his martial law declaration, which the president later clarified to mean “pro-North Korean leftists and spies.”

He further argued that this phrase suggests the so-called “collection targets” (수거 대상) listed in Noh’s notebook — approximately 500 individuals described as “left-leaning” — were being categorized as enemies within Yoon’s circle.

“That would mean that people like me, who criticize the government, are considered spies. It’s completely absurd,” said Choi, who previously served as an undersecretary-level official at the Blue House National Security Office under former President Moon Jae-in.

Then-South Korean President Moon Jae-in comforts the mother of Ahn Jong-pil, who was killed at age 16 during the 1980 Gwangju Uprising, at the National May 18 Democratic Cemetery | Image: Moon Jae-in Blue House Archives

REVIVING HISTORICAL TRAUMAS 

Yoon Kyung-hoe, a former lead researcher at the May 18 Gwangju Uprising Truth Commission, warned that South Korea’s failure to fully address past state violence has left deep scars that continue to shape political instability today.

“The root of the issue is that those responsible never faced consequences,” she said. “Many retained power, wealth and influence, and now their ideological successors mobilize using anti-communist rhetoric,” she told Korea Pro.

Former South Korean Presidents Chun Doo-hwan and Roh Tae-woo were pardoned in 1997 by then-President Kim Young-sam, despite receiving significant prison sentences for their roles in the Dec. 1979 military coup and the violent suppression of the Gwangju pro-democracy uprising in May 1980.

Currently serving as the secretary for the 5.18 Sexual Violence Victims’ Group Yeolmae (열매), Yoon Kyung-hoe works closely with survivors of historical state repression, including the 1980 Gwangju Uprising and the 1979 Busan-Masan Democratic Uprising. She said recent revelations of martial law plans from Noh have retraumatized many victims.

“Among the people I meet, many experience an overwhelming sense of fear because they were once completely at the mercy of state authorities,” Yoon said. “The trauma is stored in their bodies, and certain events can bring it all back.” 

“Ending this crisis isn’t just about politics — it’s about restoring dignity to those who suffered.”

South Korean President Yoon Suk-yeol and then-defense minister Kim Yong-hyun at the 76th Armed Forces Day parade, Oct. 1, 2024 | Image: ROK Presidential Office

A LACK OF POLITICAL RESTRAINT

Despite these significant revelations, Choi of Sangji University emphasized that the key issue remains whether Noh’s thoughts, allegedly documented in his notebook, were seriously linked to the Dec. 3 martial law plan.

While Noh’s exact role in the martial law planning remains unclear, experts have raised concerns over police evidence and strong indications of Noh’s involvement with Defense Minister Kim Yong-hyun, Counterintelligence Commander Yeo In-hyung, and others in the alleged planning at a local fast food restaurant. 

“If it continues to emerge that prominent politicians, military officials, and cabinet ministers are consulting such individuals, it signals a disturbing erosion of governance standards,” Cho Jin-man, a political science professor at Duksung Women’s University, told Korea Pro.

Cho stressed that figures like Noh, who advocate for extreme measures against political opponents, should not be allowed to influence national policy, especially martial law. 

“Self-restraint is critical. This isn’t just a legal issue — it’s a matter of political culture,” he added, emphasizing the need for leaders to resist reckless rhetoric and uphold democratic principles. 

Military personnel from the 707th Special Mission Group at the National Assembly after martial law was declared, Dec. 3, 2024 | Image: Democratic Party lawmaker Park Sun-won’s office

CHECKS AND BALANCES

As South Korea reckons with the fallout of the martial law crisis, the situation has led to questions about the role of the institutions meant to serve and protect the people.

Choi said there are now concerns that the military was exploited by “certain individuals with distorted views of the state,” reminiscent of its “problematic role” under past authoritarian governments.

However, he added that even though soldiers are bound to follow orders, they are obligated not to obey illegal commands.

Under South Korea’s Military Criminal Act, soldiers face punishment for failing to follow “lawful orders,” but some legal experts have stated that the martial law orders were illegal.

Some officers and soldiers reportedly resisted orders they believed were illegal, while Kwak Jong-geun, the then-commander of the Army Special Warfare Command, subsequently said he would refuse further martial law orders.

Choi expressed relief that there were no mass casualties or violent clashes during the martial law crisis, attributing this to the soldiers’ “restraint” in dealing with civilians.

“While the public is understandably shocked and disappointed, it is important to acknowledge that most soldiers demonstrated professionalism and civic responsibility,” he said.

To prevent such situations in the future, the former Blue House official stressed that the recent revelations from Noh’s notebook show that the country must address the consequences of its internal political stability.

“This is not a case of an external threat destabilizing South Korea — it is a crisis created from within,” he said. 

Edited by John Lee