The 'Y Operation Project', an anti-North Korean intelligence operation, was another name for the anti-North Korean intelligence operation. The North Korean agents, collectively referred to as 'Y', were called by their code numbers instead of their names. The 'Y Operation Report', a secret document of the authorities being released for the first time, shows in detail how the special missions of the North Korean agents were carried out and what their achievements were. Numerous North Korean agents were sacrificed while carrying out the 'unseen war' of intelligence operations between the South and the North. However, they were forgotten. The division of the country brought about a vicious cycle of competition between the systems and ideological confrontations between the South and the North. We look into this historical tragedy through the North Korean agents. "This is how the North Korean operation was carried out" - The 'Y' Operation Report, released for the first time The 'Y Operation Report', a secret document of the intelligence authorities, is a report on the North Korean operation mission carried out through the demilitarized zone of the central front in June 1965. The North Korean infiltration operation was carried out through the ‘North Korean Operation Plan’ and ‘Analysis of Targets and Infiltration Routes’, operation planning, training, and securing of infiltration routes. The ‘Action Progress Report’ records in detail which goals were achieved. Under the motto of ‘Work in the shadows and die in the shadows’, their existence as they carried out North Korean infiltration operations for their country was a secret known only to them. “This is how I carried out my operation” - The first publicized secret diary of a North Korean infiltration agent Park Su-cheon, a North Korean infiltration agent, was a specialist in gathering information on North Korea who carried out North Korean infiltration espionage missions with seven colleagues in 1959 and 1960. Park Su-cheon, who was directly dispatched to North Korea through the DMZ and carried out espionage activities, recorded in detail his operation activities, including information gathering, kidnapping of key figures, and assassination missions, in his secret diary. He said that although his mission was over, if his country called him again, he would carry out North Korean infiltration espionage missions right away. Victims of the ideological war and competition of systems: 'Unification through destruction of communism', 'Unification through communism', 'Let's build while fighting', etc. were very familiar words in the 1950s and 1960s, when the South and the North were engaged in a fierce ideological war and competition of systems. During this time, when both sides were armed with a thorough anti-communist ideology, the intelligence war between the South and the North was very fierce. In 1952, the Army Intelligence Corps (HID) was officially established, marking the beginning of the history of agents dispatched to the North. At that time, agent Park Bu-seo proved their existence by first disclosing the 'List of Terminated Agents', a list of 888 agents dispatched to the North. In the 1960s, North Korea's infiltration of the South became more frequent. The 1968 raid on the Blue House by Kim Shin-jo's unit led to bloody retaliation. The North Korean agents carried out retaliatory operations such as the 'Lightning Operation' and the 'Bull Operation', and the 155-mile DMZ was on the brink of war with small and large local wars taking place every day, according to the North Korean agents. Forced Silence and Forgotten Existence The total number of North Korean agents officially confirmed by the Defense Intelligence Command is 13,835. Of these, 7,726 are missing or unaccounted for. More people have disappeared than the victims of the Vietnam War. There are graves of North Korean agents left abandoned all over the DMZ, and there are testimonies that many North Korean agents are still alive in the North. The North Korean agents had to forget their names and live as forgotten existences. They risked their lives for their country and performed anti-North Korean operations on the line of death, but they were completely abandoned by the country that gave them the orders. People's Modern History Episode 36 - In the Name of the Fatherland, Y Operation Team (Aired on April 23, 2004) http://history.kbs.co.kr/