1. Kim Shin-jo's capture during the January 21st Incident. Black and white photo converted to color. 

On July 27, 1953, when the armistice agreement was signed, many believed the war had ended. The gunfire ceased, the front lines stabilized, and reconstruction began on the ruins. 

However, it was not the end of the war, but a change in its methods. While the tanks stopped, the people did not. North Korea sent agents instead of regular troops and opted for infiltration instead of all-out war. The invasion from the North had not stopped, only changed its form.

The Korean War Stopped in 1953, But the Northern Invasion Did Not

The Demilitarized Zone was not a border, but a line to catch one's breath. North Korea viewed this line not as a military demarcation line, but as a starting point to prepare for the next infiltration. This marked the beginning of espionage operations from the North.

Initially, they came down with weapons. They crossed mountains, rivers, and seas. Though disguised as civilians, their objective was not reconnaissance. It was to destroy military facilities, disrupt the rear, assassinate key figures, incite public opinion, and collapse public order. 

From the late 1950s, North Korea repeatedly deployed small armed communist groups, primarily around the Demilitarized Zone and the East Sea coast. Armed units of two to three, and sometimes up to ten, members would cross the Military Demarcation Line at night and infiltrate the rear through mountainous terrain. While their method was to gather intelligence on military deployments, road conditions, and public sentiment before returning, their activities gradually expanded from reconnaissance to sabotage and contact with residents.

Starting in the mid-1960s, North Korea became more overt. As the Park Chung-hee administration rapidly consolidated the nation's foundation through normalization of relations with Japan and economic development plans, North Korea judged that the possibility of internal collapse in South Korea had decreased. The dispatch of South Korean troops to the Vietnam War, which dispersed the ROK Army's forces, was also seen as an opportunity. 

Around 1967, North Korea simultaneously increased provocations such as incursions into the Demilitarized Zone, kidnapping fishing boats, attempts to destroy railways, and infiltration by armed spies. And in 1968, these cumulative provocations exploded all at once.

The ‘January 21st Incident’: A decapitation strike on the capital in 1968

On the night of January 21, 1968, North Korea finally targeted the heart of Seoul. This is known as the January 21st Incident. Thirty-one armed agents from Unit 124 of the North Korean Ministry of People's Armed Forces' Reconnaissance Bureau infiltrated the Blue House with the objective of assassinating President Park Chung-hee. 

They crossed the Military Demarcation Line on the night of January 17th, crossed the frozen Imjin River, passed through Sambongsan and Angmusan in Paju, and descended to the foothills of Bugaksan Mountain in Seoul. They hid in the mountains during the day and moved at night. Around 10 p.m. on January 21st, they approached the area of Segeomjeong, about 500 meters from the outer perimeter of the Blue House, near Jahamun Pass. This was the heart of Seoul. Armed agents had walked into the capital's core.

They were stopped at a police checkpoint at Jahamun Pass. Claiming to be anti-espionage agents, they attempted to pass, but as the checks continued, a shootout ensued. Superintendent Choi Gyu-sik, the head of Jongno Police Station, was killed at the scene, and the agents unleashed automatic gunfire and grenades. A grenade landed on a city bus, and civilians fell. The center of Seoul became a battlefield in the middle of the night. 

The essence of this incident was not simple espionage infiltration. The fact that North Korean special forces had reached the center of Seoul to assassinate the President of the Republic of Korea was the core issue. Kim Shin-jo, who was captured alive, stated during his interrogation that their objective was to eliminate President Park Chung-hee. North Korea sought an opportunity for regime change by eliminating the president, paralyzing the government, and causing chaos.

The mopping-up operation continued until early February. Kim Shin-jo was captured alive, and 28 were killed. Following this incident, the Homeland Reserve Forces were established, and the fence along the Demilitarized Zone and the rear anti-espionage systems were significantly reinforced. The resident registration card system and checkpoint system were also fully implemented during this period.

However, the January 21st Incident was not the end. Just two days later, on January 23rd, North Korea seized the U.S. Navy intelligence gathering ship USS Pueblo on the high seas in the East Sea. Immediately after striking the heart of Seoul, they also targeted U.S. assets, simultaneously pressuring both South Korea and the United States. North Korea's provocations in 1968 were not isolated incidents but a complex offensive that shook the entire Korean Peninsula.

The October-November 1968 Occupation Rehearsal in Uljin and Samcheok

And in the autumn of the same year, North Korea launched a larger operation. If the January 21st Incident was a decapitation strike on the capital, the infiltration into Uljin and Samcheok was a rear-area guerrilla warfare. From October 30 to November 2, 1968, North Korea infiltrated a total of 120 armed agents in three waves along the coast of Uljin and Samcheok in North Gyeongsang Province. 

The Uljin-Samcheok infiltration incident in 1968. At that time, a 10-year-old child, Lee Seung-bok, was tragically murdered by North Korean guerrillas in a mountainous village in Pyeongchang County, crying out, "I hate communists."

The agents were organized into units of 15, disguised in military uniforms, suits, and hiking gear, and sent in via the East Sea coast. These were not simple infiltration units. Their objective was not reconnaissance and return. They aimed to stay long-term in the mountainous areas of Uljin and Samcheok, incite residents, and create guerrilla bases in the rear in case of an emergency, constituting an offensive infiltration. 

At dawn on November 3rd, the reality of the situation was revealed by a report from residents of Gosu-dong, Bukmyeon, Uljin. The armed agents forcibly gathered village residents and compelled them to praise the North Korean system and join the Workers' Party and the Women's Union. Residents who resisted were stabbed with knives and beaten to death with stones. They threatened to annihilate everyone if they reported the incident. 

This was not a simple infiltration but an occupation rehearsal. North Korea was not satisfied with infiltrating secretly and observing. They intended to seize villages, incite residents, and establish guerrilla bases in the rear. The invasion from the North was evolving from reconnaissance to disruption, and from disruption to an experiment in occupation. 

However, North Korea learned one important lesson in 1968. While it was possible to come down to Seoul with guns, it was not possible to hold out for long. They failed even after reaching within 500 meters of the Blue House, and even after deploying 120 men in the mountains of Uljin and Samcheok, they were eventually wiped out. 

North Korea decided to change its strategy. Coming down with guns was shocking but lacked sustainability. To shake South Korea internally for a long time, people were more effective than guns, recruitment more effective than infiltration, and organization more efficient than arms. 

From this point on, the nature of the invasion from the North changed. Military uniforms disappeared, and suits appeared. Automatic rifles were replaced by printed materials. Underground parties emerged in place of armed agents, and revolutionary organizations began to grow in place of infiltration teams. North Korea no longer sought to hold out in the mountains for long. Instead, they aimed to hide among people for extended periods.

The Counterattack of Underground Parties in 1968: The Tongil Revolutionary Party Incident

The starting point was the Tongil Revolutionary Party incident in 1968. The Tongil Revolutionary Party incident was not a simple arrest of spies. It was an event that changed the nature of infiltration operations from the North, as North Korea attempted to create actual underground parties within South Korea. The central figure, Kim Jong-tae, contacted North Korean agents and received directives and operational funds. 

The Tongil Revolutionary Party created connections with students, intellectuals, religious circles, labor unions, and cultural groups, operating under a legal facade during peacetime. In times of emergency, it was an urban underground organization that served as a base for riots, rebellions, and paralyzing the government. 

As the 1970s progressed, North Korea also changed its infiltration routes. Direct infiltration from the North had clear limitations. The Demilitarized Zone was fortified, and coastal surveillance became more stringent. Therefore, North Korea intensified indirect operations utilizing Japan and third countries. A representative case was the Moon Se-kwang incident in 1974. 

At the National Theater during the Liberation Day ceremony, Moon Se-kwang, a Korean resident in Japan, fired a pistol at President Park Chung-hee, and First Lady Yuk Young-soo was shot and died. Moon Se-kwang was not an agent who came down from the mountains. He was an assassin who entered the event venue with a legitimate face. 

If the January 21st Incident was an event where a soldier with a gun walked into Seoul, the Moon Se-kwang incident was an event where a person in a suit entered a national event venue. North Korea's operations against the South moved from a method of hiding and infiltrating from afar to a method of blending in up close.

The 1970s Urban Underground Revolutionary Organization: The Namminjeon Incident

The Namminjeon incident in the late 1970s further clarifies this trend. The Preparatory Committee for the South Korean National Liberation Front, or Namminjeon, was an illegal underground organization formed in 1976 and exposed in 1979. While appearing to be an anti-Yushin resistance group on the surface, its internal documents and organizational structure were typical of an urban underground revolutionary organization. 

The focus was not in the mountains but around university districts, printing presses, factories, churches, and publishing networks. They used printing presses instead of guns, wore student uniforms instead of military uniforms, and used communication networks instead of radios. What North Korea most effectively sent into South Korea in the 1970s was not guns, but ideology. 

The Radicalization and Organization of the Student Movement in the 1980s

As the 1980s dawned, this trend broadened and deepened. Universities became radicalized after Gwangju, labor fields became organized, and publishing and club cultures rapidly became ideological. Of course, it would be hasty to attribute the entire democratization movement of the 1980s to North Korean operations. 

A significant portion was a self-initiated resistance against domestic political realities and the authoritarian regime. However, there is also an undeniable fact. North Korea did not leave this space vacant. 

North Korean-style discourse rapidly permeated the student movement, the labor movement, study circles, and underground publishing networks. Languages such as Juche ideology, national liberation theory, anti-Americanism, federalism, and anti-imperialism began to grow as core discourses within these movements. North Korea's cheapest success was not in issuing direct orders, but in creating strata within the country that reproduced North Korean discourse on their own. 

Post-1990s Permanent Agents and Incidents like the South Korean Workers' Party Central Region Party

In the 1990s, after the end of the Cold War, many people considered spies to be relics of the past. However, that judgment was precisely the miscalculation North Korea desired. North Korea became poorer but did not abandon its espionage. While its conventional warfare capabilities weakened, its asymmetric operations became more sophisticated. The era of coming down from the mountains with guns was over, but the era of settling into cities in suits had begun. 

The South Korean Workers' Party Central Region Party incident in 1992 marked the beginning of this trend. Even after the end of the Cold War, North Korea continued to attempt to plant underground parties within South Korea. This was done through permanent agents and internal cooperation networks, rather than armed agents. The Kim Dong-sik spy case in 1995 demonstrated that the focus of North Korean operations had shifted from infiltration to maintenance. The method was no longer about coming in once, but about harboring those who entered for a long time, maintaining them for a long time, and having them act only when necessary. 

However, North Korea still resorted to using guns when necessary. The Gangneung armed agent infiltration incident in 1996 is evidence of this. A North Korean submarine ran aground off the coast of Gangneung, and 26 agents landed and engaged in a 49-day mountain escape. The Yeosu semi-submersible incident in 1998 showed how technologically advanced North Korean operations had become. Submarines, semi-submersibles, disguised vessels, and indirect routes emerged. The poorer a regime, the more crucial asymmetric operations become. Conventional warfare is expensive, but espionage is cheap. 

The Ilsimhoe spy ring incident in 2006 represented the culmination of this trend. These were not agents from the mountains. They were individuals connected to university districts, civic groups, and political circles. North Korea's operations against the South had completely changed their form here. Military uniforms disappeared, and suits appeared. Mountains disappeared, and offices appeared. Radios disappeared, and emails and overseas contacts emerged. Spies no longer crossed mountains at night. They traveled by plane, reported via email, and met people in conference rooms. 

North Korea has never ended the war. It has only changed its uniform from guns to ideology, and from ideology to suits.

◆ Songsan

Poet and researcher of history and philosophy. Former director of the Rhee Syngman Academy. Currently serving as a research advisor for the Korean Modern and Contemporary History Research Association and as the representative of the philosophy forum Lyceum. He has published four poetry collections, co-translated "Heroes of Hook Hill," and published "Chosun: A Myth" and "Humanities on Tatami." He is currently actively engaged in research and practice of the liberal cultural movement. Songsan is a pen name.