Northwest Youth League

The Northwest Youth League was a South Korean right-wing paramilitary group that carried out anti-communist terrorism during the Cold War. Most infamously, the group massacred thousands of people in the Jeju Uprising.
History.
The Northwest Youth League was established in November 30, 1946 by refugees escaping Soviet-occupied North Korea. Murals in the Jeju April 3 Peace Park Museum state that Northwest Youth League members fought Soviets and Korean communists because “members of their family had been imprisoned, raped or murdered in North Korea, and that their property had been confiscated.”
The league conducted vigilante justice against suspected communists with no legal basis. The league was supported by Syngman Rhee, the ardent, anti-communist, US-backed autocrat of South Korea. A socialist uprising in Jeju occurred from 1948 to 1949, followed by a violent suppression campaign. According to Bruce Cumings, the league was brutal towards the residents of Jeju Island, exercising more authority than the police. An estimated 30,000 people were slaughtered in Jeju (along with 300,000 nationwide) by paramilitary groups including the Northwest Youth League. Survivors give accounts of torture used against children and mass murder. This created deep resentment in Jeju residents. What began as an anti-communist movement, quickly became a force to crush anyone who opposed President Rhee and the Korea Democratic Party.
A decade after the Korean War, Rhee was forced into exile after the April Revolution in South Korea. Anti-communism remained a powerful force, especially during the dictatorships of Park Chung-hee and Chun Doo-Hwan.