- The Battle of Khe Sanh was conducted northwestern Quaag Tri Province, South Vietnam, between January 21 and July 9, 1968 during the Vietnam War. It involved elements of the United States III Marine Amphibious Force, 1st Cavalry Division, the US 7th Air Force, 1st Battalion 9th Marine Regiment, and minor elements of the South Vietnamese Army against two to three division-size elements of the North Vietnamese Army.