A town located in northeastern Quang Tri Province in I Corps, Dong Ha provided the southeast anchor of "Leatherneck Square," a defensive barrier along the DMZ. At the junction of Highways 1 and 9 (the only major north-south and east-west land lines) and accessible to the Cua Viet River system, this proved to be an ideal site for the Dong Ha Combat Base (DHCB). Located one kilometer south of the town, DHCB served as 3d Marine Division headquarters and logistics center for III Marine Amphibious Forces units.
After the 1968 Tet Offensive, the Democratic Republic of Vietnam (DRV)/National Liberation Front's (NLF's) strategy of improving their bargaining position at the upcoming Paris peace talks was to prepare for successful military action that led to 119 attacks on civilian and military targets. As the 3d Marine Division was preparing a counteroffensive to attack PAVN units along the DMZ, on April 29 elements of the PAVN 320th Division were spotted about four miles north of the DHCB. The 1st and 2d Battalions, 2d Regiment, 1st ARVN Division made contact with a PAVN regiment along Route 1. The 2d Battalion, 4th Marines ("Magnificent Bastards") engaged the PAVN main force in fierce fighting at Dai Do hamlet, one and one-half miles northeast of Dong Ha. After three days of hard fighting, the 1st Battalion, 3d Marines relieved the 2d Battalion, 4th Marines for an additional three days at Dai Do. The 3d Battalion, 21st Infantry ("Gimlets"), 196th Light Infantry Brigade, American Division (under the operational command of the 3d Marines) shared in taking the brunt of the PAVN attack in a bitter battle at Nhi Ha, six miles northeast of Dong Ha. On May 16 the PAVN 320th Division was able to break off contact (that division returned in late May, once again met the 2d Battalion, 4th Marines and, and by the end of the month, was temporarily combat ineffective).
Other Marine units (in order of insertion: 3/3d, 1/9th, 3/9th, 1/26th) saw significant combat, as did the ARVN 1st Division. The 1st and 2d Battalions, 5th Cavalry, 1st Cavalry Division (Airmobile), with its units positioned from northeast of Nhi Ha to north of Dong Ha, operated under the 3d Marines on May 6-17 and called its participation Operation CONCORDIA.
Total casualties in units under operational control of the 3d Marines numbered 233 killed, 821 wounded, and 1 missing in action. ARVN casualties were estimated at 42 killed and 124 wounded. The PAVN reportedly lost 2,366 dead and 43 prisoners. Dong Ha retained its role as command and logistics center until turned over to the ARVN in November 1969. Paul S. Daum, with assistance from B. J. Rogers
Nolan, Keith William. The Magnificent Bastards: The Joint Army-Marine Defense of Dong Ha, 1968. Novato, CA: Presidio Press, 1994.; Olson, James S., ed. Dictionary of the Vietnam War. New York: Greenwood Press, 1988.; Simmons, Edwin H. "Marine Corps Operations in Vietnam, 1968." in The Marines in Vietnam, 1954-1973: An Anthology and Annotated Bibliography. Marine Corps Vietnam Series. Washington, DC: History and Museums Division, U.S. Marine Corps Headquarters, 1974.
Paul S. Daum, with assistance from B. J. Rogers