During the Vietnam War, the Republic of Korea sent more combat troops to South Vietnam than any other American ally. A South Korean liaison unit came to Vietnam in the summer of 1964, and between 1965 and late 1966 their Capital Division, Ninth Infantry Division, and Second Marine Brigade arrived. South Koreans concentrated their combat efforts in II Corps. By 1969, there were almost 49,000 South Koreans fighting in South Vietnam. During the entire war, the South Koreans suffered 4,407 combat deaths. The Capital and Ninth divisions were withdrawn from South Vietnam in March 1973. South Korea's loyalty to the American war effort in South Vietnam, even though most Korean officials did not think the war was politically winnable, was a direct function of the close relationship existing between the two countries since the Korean War (1950-53).