The ượngĐứBattle of Thượng Ðức was a battle of the Vietnam War which began on 29 July and concluded on 11 November 1974.
Background
Thượng Ðức District was located 40 km southwest of Danang. It was accessible by a single road, local Route 4 which followed the north bank of the Song Vu Gia river, passed through a narrow defile between the hills and the river and then entered the district town of Thượng Ðức. The Song Vu Gia valley was only 3 km wide here; steep hills overlooked Thượng Ðức town on the north, west, and south. There were no villages outside the district town itself secure enough for South Vietnamese officials to spend the night, and only three villages in the district had government administration by day. People's Army of Vietnam (PAVN) lines of communication from the northwest and southwest reached Thượng Ðức via Route 14, which terminated there, and Route 614, which began in the large PAVN logistical complex south of the A Sau Valley and joined Route 4 west of Thượng Ðức. This district, therefore, was a key entrance to the Quang Nam Province lowlands.
Battle
On 18 July 1974, the PAVN 29th Regiment, 324th Division overran the An Hoa Industrial Complex and then on 29 July attacked the town of Thượng Ðức, which was defended by Army of the Republic of Vietnam (ARVN) 79th Ranger Battalion. The PAVN shelling of Thượng Ðức was followed by infantry assaults on all outposts. Communication was quickly broken between Thượng Ðức Subsector and three Popular Force outposts. Contact was also lost with two Ranger outposts in the hills west of the town. ARVN artillery on Hill 52 (), near Đại Lộc District, gave effective support to the Thượng Ðức defense and PAVN casualties were high. Early on the morning of 30 July, the subsector commander was wounded by the continuing heavy bombardment, but all ground attacks were repulsed. Later that morning Republic of Vietnam Air Force (RVNAF) observers saw a convoy of tanks and artillery approaching along Route 4 west of Thượng Ðức, and subsequent air strikes halted the column, destroying three tanks. As PAVN attacks continued throughout the day, the Rangers took their first prisoner of war, and identified the presence of the 29th Regiment on the battlefield.
In an assault on 31 July, PAVN infantrymen reached the perimeter wire of Thượng Ðức. The Ranger battalion commander asked for artillery fire directly on his command post. With the PAVN occupying the high ground above Route 4 east of Thượng Ðức, the ARVN 3rd Division commander General Nguyen Duy Hinh and I Corps commander General Ngô Quang Trưởng believed that the forces available to them were inadequate to relieve Thượng Ðức. To protect his flank, Hinh had placed the battered 2nd Infantry Regiment on the road west of Đại Lộc, but it was not strong enough to move west along Route 4. More fire support for Thượng Ðức was provided, however, when Hinh moved a platoon of 175mm guns to Hieu Duc. Conditions in the Thượng Ðức perimeter were serious but not yet critical. Most of the South Vietnamese bunkers and trenches had collapsed under heavy artillery fire, the PAVN controlled the airstrip just outside the camp, and casualties were 13 killed and 45 wounded. Although the intensity of the PAVN bombardment dropped off between 31 July and 1 August, Ranger casualties continued to mount. PAVN gunners shifted their concentrations to 2nd Infantry positions and artillery batteries near Đại Lộc, causing moderate casualties and damaging four howitzers. The Ranger commander at Thượng Ðức asked for medical evacuation for his wounded, but the commander of the RVNAF 1st Air Division advised that air evacuation would not be attempted until the PAVN antiaircraft guns around Thượng Ðức had been neutralized. Meanwhile, Trưởng ordered one M48 tank company to move immediately from northern I Corps to Quang Nam for attachment to the 3rd Division; he told Hinh to keep the tank company in reserve and to employ it only in an emergency. Hinh then formed a task force to attack west from Đại Lộc and relieve the Rangers at Thượng Ðức. The tank company from Tân Mỹ Base, in Thừa Thiên province, arrived in Da Nang in good order on 1 August, and Hinh's task force, composed of the 2nd Infantry and the 11th Armored Cavalry Squadron, prepared for the march to Thượng Ðức.