The Hue–Da Nang Campaign was a series of military actions conducted by the People's Army of Vietnam (PAVN) against the Army of the Republic of Vietnam (ARVN) during the Vietnam War, also known in Vietnam as the American War. The campaign was centred on the cities of Huế (Thừa Thiên-Huế Province) and Da Nang (Quảng Nam Province), with secondary fronts in the provinces of Quảng Trị and Quảng Ngãi. The campaign began on March 5 and concluded on April 2, 1975.
During the spring season of 1975, the PAVN High Command in Hanoi made the decision to seize the major South Vietnamese cities of Huế and Da Nang, and also destroy the various South Vietnamese units in I Corps Tactical Zone, led by ARVN General Ngô Quang Trưởng. Originally, the campaign was planned to take place over two phases; during the seasons of spring-summer and autumn. However, as the North Vietnamese forces rolled over South Vietnamese defences on the outskirts of Huế and Da Nang, President Nguyễn Văn Thiệu ordered General Trưởng to abandon all territories under his control, and pull his forces back to the coastal areas of I Corps. The South Vietnamese withdrawal quickly turned into a rout, as the PAVN 2nd Army Corps picked off one South Vietnamese unit after another, until Huế and Da Nang were completely surrounded. By March 29, 1975, PAVN troops had full control of Huế and Da Nang, while South Vietnam lost all territories and most of the units belonging to I Corps.
On March 31, ARVN General Phạm Văn Phú—commander of II Corps Tactical Zone—attempted to form a new defensive line from Qui Nhơn to cover the retreat of the ARVN 22nd Infantry Division, but they too were destroyed by the PAVN. By April 2, South Vietnam had lost control of the northern provinces, as well as two army corps.
Background
North Vietnam
During the Huế–Da Nang Campaign of 1975, North Vietnamese and Viet Cong (VC) forces were organised into three formations; the PAVN 2nd Corps, Tri Thien Military Zone, and Military Region 5 Command. The 2nd Corps fielded three infantry divisions (304th, 324B and 325C Divisions), the 673rd Air-Defence Division, the 164th Artillery Brigade, the 203rd Armoured Regiment, the 219th Combat Engineers Brigade, and the 463rd Communications Regiment. The 2nd Corps was led by Major-General Nguyễn Hữu An, with Major-General Le Linh as Political Commissar. Colonel Hoang Dan was the deputy commander, and Colonel Nguyen Cong Trang was the deputy political commissar.
Led by Major-General Lê Tự Đồng, the Tri Thien Military Zone had three infantry regiments (4th, 46th and 271st Regiments), and two battalions (the 21st Independent Battalion and the 6th Local Force Battalion). Military Region 5 had one infantry division (2nd Division), which was supported by the 141st Regiment (from the 3rd Division), the 52nd Independent Brigade, two artillery regiments (368th and 572nd Artillery Regiments), two local battalions (70th and 72nd Local Force Battalions), and two local regiments (94th and 96th Local Force Regiments). North Vietnamese and Viet Cong units of Military Region 5 were placed under the responsibility of Major-General Chu Huy Mân, with Vo Chi Cong as political commissar.
Objectives
Tri Thien
On February 21, 1975, PAVN field commanders from Tri-Thien Military Zone and the 2nd Army Corps held a conference to establish their objectives, which were planned to occur in two phases; the spring-summer phase that would begin in March and probably conclude in May, and the autumn phase to last from July to August 1975. The PAVN objective was to take control of Quảng Trị Province, isolate the city of Huế and, if the opportunity presented itself, capture the entire Tri Thien-Huế area. To isolate Huế, the PAVN 2nd Army Corps would move against their target from the north-west direction along Route 12 down to the south-west along Highway 14, thereby isolating the region from South Vietnamese forces in II Corps Tactical Zone.
In preparation for the Huế–Da Nang Campaign, the PAVN 2nd Army Corps had successfully captured several important base areas that surrounded South Vietnamese units in Quảng Trị Province and Thừa Thiên Province. Those areas included Đông Hà–Ái Tử to the north, Khe Sanh-Ba Long to the west, and A Lưới-Nam Dong in southern Huế. The main body of the 304th Division and the 3rd Regiment, 324th Division, had assembled in Nong Son and Thường Đức to attack Da Nang from the west. In Military Region 5, the 2nd Division had established its positions in Tiên Phước, Tra My and Trà Bồng in Quảng Ngãi Province, and Đắk Tô and Tân Cảnh in Kon Tum Province.
Quảng Tin-Quảng Ngãi
Once Huế had been isolated, Military Region 5 Command would initiate the Tin-Ngai Campaign from the provinces of Quảng Tin and Quảng Ngãi, to isolate Da Nang from the Central Highlands. PAVN units such as the 2nd Division, the 141st Regiment, the 52nd Brigade, along with two artillery regiments (368th and 572nd Artillery Regiments) would coordinate their efforts with the VC 94th and 96th Local Force Regiments, and the 70th and 72nd Local Force Battalions. As part of their overall objective, they would tie down the ARVN 2nd Division, the 11th Armoured Squadron and the 912th Regional Force Company in Quảng Ngãi Province, and, if the opportunity arose, they would also capture Bình Định Province and the city of Qui Nhơn.
Da Nang
In the final phase of their operation, the PAVN and VC would cut off Da Nang from the surrounding regions which made up I Corps Tactical Zone, and prevent reinforcements from retaking the city. Then, depending on the situation, the PAVN would organize an attack to capture the major South Vietnamese army, navy and air force installations in the city.
South Vietnam
South Vietnamese military forces in Huế and Da Nang belonged to the ARVN I Corps Tactical Zone. Commanded by Lieutenant General Ngô Quang Trưởng, the South Vietnamese I Corps was considered to be the strongest amongst all the military formations of South Vietnam. It had three infantry divisions (1st, 2nd and 3rd Infantry Divisions), the Airborne Division (led by Major General Le Quang Luong), the Marine Division (led by Major General Bui The Lan) and the 11th, 12th, 14th and 15th Ranger Groups. The Airborne and Marine Divisions each had an assigned strength of four brigades. In addition to the infantry units, there were also the 5th Armoured Brigade, five squadrons of armored vehicles (4th, 7th, 11th, 17th and 20th Armored Squadrons), 13 armored companies, and 21 artillery battalions.
Local defense in I Corps was provided by 50 battalions and five companies of Regional and Popular Forces, and six companies of military police. Support for ground forces in the area came in the form of the Republic of Vietnam Air Force (RVNAF) 1st Air Force Division (commanded by Brigadier-General Nguyen Van Khanh), with two Republic of Vietnam Navy squadrons operating on the coast and another two along the rivers. Overall, I Corps fielded about 134,000 soldiers; 84,000 were regular soldiers and 50,000 belonged to the Regional and Popular Forces. Those forces were equipped with 449 tanks and armored vehicles, 418 artillery pieces, 64 M42 Duster light air-defense weapons, 373 aircraft of different types, and 165 naval vessels of different sizes.
Defensive strategy
In combination with the ‘Ly Thuong Kiet Military Plan’ and experiences gained during the North Vietnamese Easter Offensive, Trưởng organised the defenses of I Corps into three phases, to be staged from three different areas.
Defensive phases
The first phase, known as the ‘orange phase’, was considered to be the most important because it provided South Vietnamese units in I Corps with a platform to stop enemy attacks, and even attack them if necessary. To accomplish the objectives of the ‘orange phase’, Trưởng placed several elite combat units such as the Ranger groups and armoured forces on constant combat alert. The second phase, known as the ‘green phase’, was designed to delay enemy forces and buy more time for the South Vietnamese to regroup in order to stage a counter-attack, in the scenario that enemy forces managed to overcome the ‘orange phase’. In the final phase, or the ‘blue phases’, require South Vietnamese units to secure their areas of defence, then destroy and push enemy forces out of I Corps.
Areas of defence
Trưởng's areas of defence were centred on Tri Thien-Huế, Da Nang, and Quảng Nam-Quảng Ngãi.
Tri Thien-Huế
The task of holding Tri Thien and Huế was entrusted to the 1st Division, the 4th and 15th Ranger Groups, the 913th and 914th Regional Forces Companies, the 17th and 20th Armoured Squadrons, 10 artillery battalions, one squadron of helicopters, two squadrons of reconnaissance aircraft, and one coastal patrol squadron. Those forces were commanded by Lieutenant general Lâm Quang Thi.
Nam-Da Nang
Da Nang was under the direct responsibility of Trưởng. It was home of the 3rd Division, the 4th and 7th Armoured Squadrons, the 11th and 14th Ranger Groups, the 911th Regional Force Company, the 1st Air Force Division, one coastal patrol squadron and two riverine squadrons.
Quảng Tin-Quảng Ngãi
Quảng Tin and Quảng Ngãi was held by the 2nd Division, the 12th Ranger Group, the 11th Armoured Squadron, three artillery battalions, the 912th Regional Force Company, one coastal patrol squadron and one riverine squadron. Brigadier-General Trần Văn Nhựt commanded the 3rd Infantry Division, and all other units in Quảng Nam and Quảng Ngãi.
Prelude
On March 5, 1975, the PAVN 2nd Army Corps officially commenced its campaign against South Vietnamese forces of I Corps. The opening shots of the campaign was marked by an attack on South Vietnamese military convoys on the Hai Van Pass and the destruction of An Lo Bridge on Highway 1, located north of Huế. Positions held by the ARVN 913th Regional Force at Dong Ong Do and Hill 368 also came under attack, as Phu Bai Airbase was subjected to intense artillery bombardment. While the South Vietnamese were busy dealing with those attacks, General Nguyen Huu An secretly redeployed the 325th Division and the 9th Regiment of the 304th Division, from Quảng Trị towards Huế in the south. The 46th and 271st Regiments then moved into positions previously held by the 325th Division and 9th Regiment. In order to fool South Vietnamese intelligence agencies, the North Vietnamese moved tank and artillery units to Cua Viet, Thanh Hoi and Ai Tu to cover their main thrust.
Between March 6 and 7, the VC 4th Local Force Battalion assaulted and overran Mai Linh and 11 other surrounding military sub-sectors in Quảng Trị Province. On the following day, General Lâm requested reinforcements from General Trưởng in Da Nang, as a response to PAVN attacks in his area of control. Meanwhile, the PAVN 2nd Army Corps continued their onslaught, with the 324th Division launching attacks on South Vietnamese positions on Núi Bong (16°17′10″N 107°44′31″E / 16.286°N 107.742°E) and Núi Mô Tau (16°18′25″N 107°39′36″E / 16.307°N 107.66°E) and on Hills 75, 76, 224 (16°16′30″N 107°44′49″E / 16.275°N 107.747°E), 273 (16°16′N 107°44′E / 16.26°N 107.73°E) and 303 all located near Phú Lộc, south of Huế and north of the Hai Van Pass.
By March 10, the 1st Battalion, 54th Infantry Regiment, 1st Division was destroyed on Hills 224 and 273; the ARVN 47th Armoured Squadron was overrun by the PAVN 1st Regiment, 324th Division, on Mount Nghe; and the ARVN 113th Regional Force Battalion conceded Pho Lai to the PAVN 4th Regiment, which was supported by the 223rd Artillery Regiment. Thi then ordered the 15th Ranger Group and the 2nd Battalion, 54th Infantry Regiment, with support from the 27th and 37th Tank Squadrons, to mount a counter-attack on Hill 224. Over the period of one week, both sides fired over 8,000 rounds of artillery shells on Hill 224, and the RVNAF conducted over 60 bombing sorties in an attempt to halt the advances of the PAVN 2nd Corps.
On March 13, amidst heavy fighting in the northern provinces, Trưởng flew to Saigon for a meeting with President Nguyễn Văn Thiệu. In this meeting, Thiệu outlined his decision to abandon most of the provinces in I Corps, and ordered Trưởng to withdraw his forces towards the coastal regions of central Vietnam instead. In addition, the Airborne Division would be redeployed to the Mekong Delta region, where it could protect the nation's capital. Unwilling to concede the northern provinces to the enemy, Trưởng tried unsuccessfully to convince Thiệu to reverse his decision in the belief that he could hold onto I Corps, and recapture lost territories by using the Airborne and Marine Corps Divisions. After he returned to his headquarters that afternoon, Trưởng decided to redeploy his forces instead of carrying out Thiệu's order straightaway, for several reasons. Firstly, he wanted to convince the President that most South Vietnamese units were still intact and that they still had the time to recapture lost territories, and secondly, Trưởng did not want to create confusion amongst his subordinates, when the military situation in I Corps was still under control.
Thus, Trưởng reorganised his defences in order to deal with the threat posed by PAVN formations located south of I Corps; he designated Da Nang to be the main centre of South Vietnamese defence in I Corps, with Tri Thien in the north, and with Quảng Nam and Quảng Ngãi in the south. To make up for the loss of the Airborne Division, Trưởng ordered the 369th Marine Brigade to replace the 3rd Airborne Brigade in Quảng Nam Province, and the 258th Marine Brigade to take over from the 2nd Airborne Brigade on Mount Phu Gia, located north of Hai Van.