South Korea in the Vietnam War

South Korea, which was at the time an hybrid regime under its right-wing president Park Chung Hee, took a major active role in the Vietnam War. The Korean War just a decade prior was still fresh on the minds of the South Korean people, and the threat from North Korea was still very real. South Korea's decision to join resulted from various underlying causes. This included the climate of the Cold War, to further develop of South Korea–United States relations for economic and military support and political exigencies like anti-communism. Under the wartime alliance, the South Korean economy flourished, receiving tens of billions of dollars in grants, loans, subsidies, technology transfers, and preferential economic treatment.

From September 1964 to March 1973, South Korea sent some 350,000 troops to South Vietnam. The South Korean Army, Marine Corps, Navy, and Air Force all participated as an ally of the United States. The number of troops from South Korea was much greater than those from Australia and New Zealand, and second only to the U.S. military force for foreign troops located in South Vietnam. The military commander was Lieutenant general Chae Myung-shin of the South Korean army. Participation of South Korean forces in the war included both non-combatant and combatant roles. Its role was also not without controversy, with South Korean forces having committed numerous war crimes in Vietnam, issues that still affect contemporary South Korea–Vietnam relations due to South Korea's indifferent stance.