Operation Rat Killer

Operation Rat Killer was an operation carried out by Republic of Korea forces and United States advisors in from December 1951 into February 1952 during the Korean War. It was aimed at eradicating communist guerilla forces operating in zones occupied by the United Nations forces. The operation involved two Korean Army divisions, the Capital Division and the 8th Division, several regiments of the Korean National Police, a ROKAF squadron of Mustang fighter-bombers, and about sixty United States experts. The operation was under the command of General Paik Sun Yup. The operation's particular priority area was the mountainous area of Jirisan.

Before the operation, the guerilla was allegedly responsible for harassing nearly a third of UN forces and conducting regular attacks on roads and railways used by them. After the operation, the guerilla forces were greatly weakened, although a resurgence remained a threat until the end of the war.

Background

In 1951, a large number of communist guerilla groups, ranging in size from a few hundred to several thousand, were operating in territory supposedly controlled by UN forces and were attacking roads and railways, sniping at UN forces, and raising funds from local inhabitants. These guerilla bands were particularly active in the Jirisan mountains, although sniping and guerilla activity had been reported even in the area of the capital, Seoul. Local anti-communist militias formed themselves to fight back, sometimes engaging in savage reprisals against villages deemed to be supporting the guerilla.

Outcome

After the operation, communist guerilla forces were greatly weakened, although thousands of Republic of Korea police were required to remain in the area, supported by up to 11,000 local militia known as the Young Volunteers, in order to prevent the resurgence of the remaining guerilla forces who may have numbered about 3,000.

According to Republic of Korea records, 5,800 guerilla fighters were killed and 5,700 were captured. US records claim 9,000 guerilla fighters were killed, while some sources estimate as many as 10,000.