In August 1945, the Soviet Union declared war on the Empire of Japan and carried out an invasion operation on the Korean Peninsula. To prevent the Soviet occupation of the Korean Peninsula, the United States established a military demarcation line along the 38th parallel. In 1948, the division began with the establishment of separate governments in South and North Korea. On June 25, 1950, the Korean War broke out due to a surprise invasion by North Korea, and after three years of war, an armistice agreement was signed in July 1953.
After the armistice, the Korean Peninsula became a stage where the global Cold War system was spatially manifested, placing inter-Korean relations at the forefront of bloc confrontation. The prolonged Cold War confrontation structure began to dissolve following the collapse of the Soviet and Eastern European socialist systems in the 1990s. The government inaugurated in 1998 promoted the Policy of Reconciliation and Cooperation toward North Korea, which focused on humanitarian aid and economic exchange with North Korea. Also known as the Sunshine Policy, this aimed to alleviate tensions and induce reform and openness in North Korea through direct dialogue, marking a departure from previous hardline policies. The Policy of Reconciliation and Cooperation led to the first inter-Korean summit in June 2000, resulting in the June 15th North-South Joint Declaration, which outlined a basic agreement for peaceful reunification of the Korean Peninsula.
The succeeding administration maintained a similar stance toward North Korea, resulting in the second inter-Korean summit in October 2007. At this summit, the October 4th North-South Joint Declaration was adopted, reaffirming the spirit of the June 15th declaration and including agreements on the development of inter-Korean relations, peace on the Korean Peninsula, and joint prosperity and reunification of the Korean people.
However, during the Lee Myung-bak Administration in 2008, inter-Korean relations rapidly deteriorated. North Korea continued provocations against South Korea, including a second nuclear test and the Battle of Daecheong in 2009, as well as the sinking of the ROKS Cheonan warship and the shelling of Yeonpyeong Island in 2010, resulting in casualties. This tense situation persisted under the Park Geun-hye Administration, with North Korea conducting its third and fourth nuclear
tests, planting landmines in the DMZ, shelling the western front, and firing multiple missiles and rockets. In particular, skepticism about efforts to improve inter-Korean relations grew following the complete shutdown of the Kaesong Industrial Complex, established as part of the Policy of Reconciliation and Cooperation, in 2016.
The third inter-Korean summit took place in 2018 amid an atmosphere conducive to peace and dialogue on the Korean Peninsula, created in part by the PyeongChang Winter Olympics. The summit was held three times that year: in April and May at Panmunjom and in September in Pyongyang.
At the summit held on April 27, 2018, at the Peace House on the South Korean side of Panmunjom, the two Koreas announced the Panmunjom Declaration for Peace, Prosperity, and Reunification of the Korean Peninsula, which included steps for a declaration to end the Korean War, the establishment of a peace regime, the installation of a direct communication line, and the establishment of a joint liaison office. This was followed by a fourth, unpublicized summit held on May 26, 2018, at Tongilgak on the North Korean side of Panmunjom. The fifth summit was held September 19–20, 2018, in Pyongyang, leading to the adoption of the September 19 Pyongyang Joint Declaration, which included agreements in various fields such as military, economic cooperation, and family reunions, and the September 19 Military Agreement aimed at ending hostile acts, withdrawing guard posts in the DMZ, and creating a maritime peace zone in the West Sea. However, North Korea resumed launching short-range missiles and coastal artillery the following year, violating the September 19 Military Agreement. Relations rapidly cooled again following the destruction of the Inter-Korean Liaison Office located in the Kaesong Industrial Complex in June 2020.
There was little inter-Korean exchange and cooperation until the 1960s. In the 1970s, dialogue began on humanitarian grounds with the Red Cross Talks initiated by South Korea, leading to the 1972 July 4th North-South Joint Statement, which agreed on three principles for peaceful reunification: independence, peace, and national unity. In 1984, South Korea’s response to severe flooding by providing aid to North Korea opened the way for inter-Korean exchanges. The following year, in 1985, the first family reunions and cultural exchange visits occurred. On November 8, 1994, the Kim Young-sam Administration announced the first measure to revitalize inter-Korean economic cooperation, which was further advanced by the second measure announced on April 30, 1998, during the Kim Dae-jung Administration, and the inter-Korean summit in June 2000.
Inter-Korean economic cooperation initially began with general trade, including commodity trading, and then expanded to include consignment processing trade and direct investment. General trade and consignment processing accounted for a large proportion of imports from North to South Korea. From 2010, the amount imported from economic cooperation projects, such as the Kaesong Industrial Complex, Mount Kumgang tourism, and other light industry cooperation, surpassed general trade and consignment processing for the first time. A similar pattern was seen in exports from South to North Korea, where non-commercial transactions dominated initially, but economic cooperation gradually increased.
Progress in inter-Korean economic cooperation also positively affected family reunions. From 2000 to 2010, during the peak of economic exchanges, various forms of family reunions were held at both private and governmental levels, including verification of life status, letter exchanges, and reunions, with a total of 18 direct and video reunions conducted. However, due to the fluctuating inter-Korean relations, it became challenging to conduct events smoothly, with only three additional reunions held through 2018.
During the Moon Jae-in Administration, inter-Korean exchanges were notably evident in cultural and artistic fields, with South and North Korean athletes forming unified teams for various international competitions. At the 2018 PyeongChang Winter Olympics, a unified women’s ice hockey team competed, and at the Jakarta-Palembang Asian Games later that year, unified men’s and women’s dragon boat teams and a women’s basketball team competed, achieving notable successes. Additionally, mutual visits by South and North Korean art troupes were realized for the first time in 11 years. Various exchanges in sports, academia, and cultural heritage were actively conducted, including the joint excavation of the Manwoldae site in Kaesong from October to December 2018.
Major inter-Korean economic cooperation projects included tourism in Mount Kumgang, development of the Kaesong Industrial Complex, and the inter-Korean railway and road connection projects. Mount Kumgang tourism began with the signing of the Agreement on the Development of Mount Kumgang Tourism and Joint Advancement into Siberia in 1989 by the late Hyundai Group Honorary Chairman Chung Ju-yung, with the first tour conducted in 1998. More than 40 South Korean companies, including Hyundai Asan and the Korea Tourism Organization, participated, and in November 2002, North Korea designated the area as a special tourism zone through the Mount Kumgang Tourism District Law. Before its suspension following the fatal shooting of a South Korean tourist in 2008, the Mount Kumgang tourism project had attracted around 2 million visitors.
The Kaesong Industrial Complex project began in August 2000 with an agreement between Hyundai Asan in the South and the Asia-Pacific Peace Committee in the North. Development of the first phase, covering 3.3 million square meters, began on June 30, 2003, with companies starting to move in by 2005. In April 2013, the complex was closed due to North Korea’s strong opposition to South Korea-U. S. joint military exercises. However, in August of the same year, the two Koreas reached a dramatic agreement to resume operations. Nevertheless, in 2016, following North Korea’s nuclear test, inter-Korean relations quickly deteriorated, leading to its closure. As of 2024, operations remain suspended. Before the closure, the Kaesong Industrial Complex housed approximately 55,000 workers from both Koreas and 125 companies, with cumulative production worth USD 3.23 billion.
The 1991 Basic Agreement between the South and North included provisions for reconnecting severed railways and roads and opening maritime and air routes. At the first and second inter-Korean ministerial talks held in 2000, the two sides agreed to connect the Gyeongui Line railway (Seoul—Sinuiju) and road (Munsan—Kaesong). In early 2003, temporary passage for the Kaesong Industrial Complex development began via the Gyeongui Line road, and the Donghae Line road was also opened for Mount Kumgang land tourism after the opening ceremony on February 11, 2003. In May 2007, test runs of trains were conducted between Munsan Station and Kaesong Station on the Gyeongui Line and between Geumgangsan Station and Jejin Station on the Donghae Line. Regular freight train services between Munsan and Kaesong (Bongdong) began in December of the same year. However, due to the deteriorating inter-Korean relations, train operations were suspended in December 2008, and the Donghae Line road operation was halted in July 2008. As of 2024, all related projects are suspended.
In the Panmunjom Declaration, adopted at the first inter-Korean summit in 2018, South and North Korea initially agreed to connect and modernize the East and Gyeongui railway lines and roads for their utilization. As a follow-up measure, the Inter-Korean Railway Cooperation Subcommittee meeting, held on June 26, 2018 for the first time in 10 years, decided to jointly inspect the sections for inter-Korean railway connections and conduct an on-site joint survey in North Korea as a preliminary project for the modernization of the East and Gyeongui railway lines. As a result, from November 30 for 18 days, a joint survey was conducted on the Gyeongui Line section from Kaesong to Sinuiju (approximately 400 km) and the East Sea Line section from Mount Kumgang to the Tumen River (approximately 800 km), and a groundbreaking ceremony was held at Panmun Station in Kaesong on December 26.
At the third inter-Korean summit held in Pyongyang in September, the Pyongyang Joint Declaration included agreements on military measures to end the military hostile relations, inter-Korean economic cooperation, humanitarian cooperation, and various other areas. As an annex to the Pyongyang Joint Declaration, the Military Agreement on the Implementation of the Historic Panmunjom Declaration, also known as the September 19 Military Agreement, was adopted. The September 19 Military Agreement covers existing inter-Korean military agreements, including the cessation of hostile acts, the establishment of a peace zone in the DMZ, the creation of a West Sea peace zone, military assurances necessary for exchange and cooperation, and measures to build military trust. As a practical measure, a mine removal operation was conducted in the Arrowhead Ridge area of Cheorwon, Gangwon Province, on October 1, 2018, for the joint recovery of remains. At the same time, the demilitarization of the Joint Security Area (JSA) began, including the withdrawal of guard posts and firearms, personnel adjustments, and joint verification by the South, North, and the United Nations Command, which was completed by the end of October. Additionally, on November 1, a trial withdrawal of guard posts within 1 km of each other in the DMZ was carried out, and by November 30, the dismantling and destruction of ten DMZ guard posts was completed, except for one that was preserved.
The Yoon Suk-yeol government, inaugurated in 2022, has so far taken a firm stance toward North Korea. The government has determined that North Korea continues provocative acts, such as launching cruise missiles and ballistic missiles, which constitute a total violation of the September 19 Military Agreement. In response, the government maintains a strong policy stance toward North Korea, including imposing independent sanctions on North Korean individuals and institutions involved in the development of weapons of mass destruction and missiles. Furthermore, in 2024, the government enacted the North Korean Human Rights Act and established related institutions and organizations to protect and promote the human rights of North Korean residents.