Chae Myung-shin commanded Skeleton Corps , guerrilla corps during the Korean War, and became the authority on guerrilla tactics of the South Korean Army. Chae commented on South Korean comfort women units during the Korean War in his memoir Beyond the Deadline ( 사선을 넘고넘어 ) published in 1994. 
Chae served as a ROKFV Commanding Officer during the Vietnam War. Chae adopted strong tactics for the Vietnamese as an authority on guerrilla tactics. Chae's harsh policy caused a serious disagreement with William Westmoreland, the chief of staff of the United States Forces.  When the Phong Nhị and Phong Nhất massacre occurred, William Westmoreland several times demanded Chae Myung-shin should investigate.   Chae replied the criminals were Viet Cong.  During the Vietnam War, Chae concurrently served as the Chief of Staff of the ROK Army, and subsequently wrote a Vietnam War memoir titled "The Vietnam War and I".