Operation Nong Son – Thuong Duc in 1974 of our military and people completely destroyed hardened military fortifications and a large number of enemy troops, breaking the enemy’s defensive system in the theatre of Quang Da, Quang Nam. Victory of the operation contributed to creation of posture and strength for the 1975 General Offensive and Uprising and marked a development in the art of combined arms combat.

In early 1974, in the face of our fierce attacks across the Southern theatre of war, there were clear signals that the enemy was weakening. By the mid-1974, there were hardly any offensive operations. The enemy could only launch some rescue, interdiction operations defensive in nature in areas under our direct pressure. They tended to abandon peripheral fortresses and retreat into existing major fortifications. The enemy deployed the majority of their strength and weapons in Nong Son and Thuong Duc, the key outposts in charge of defending Da Nang joint military base from the west. Additionally, the enemy air force and artillery were always ready to provide the base with fire support to threaten and attack our rear.

Consecutive victories in the theatres of war offered us windows of opportunity to inflict great losses on the enemy’s regular forces. In January 1974, the 5th Military Region Party Committee’s Standing Board directed conduct of major military activities. Our regular forces were ordered to engage the enemy with increasing frequency and expanded liberated areas. The local armed forces and people revolted to create overwhelming force, striving for decimating many enemy troops. Accordingly, since May 1974, the 5th Military Region armed forces undertook military activities in key areas, including Thuong Duc, Nong Son – Trung Phuoc, Route 16 – Que Son, and Nghia Hanh. With the resolution to dislodge the enemy troops from important positions, open a land corridor between western Quang Da and the flat plain of Quang Nam – Da Nang, and create position and strength for strategic activities in 1974-75 dry season, the Military Region decided to launch Operation Nong Son – Thuong Duc. Under the leadership of the 5th Military Region Party Committee’s Standing Board and Command, most notably the Operation's Party Committee and Command, our military and people annihilated a large number of enemy troops, captured two military fortifications and the military division of Nong Son – Thuong Duc, and liberated a large area, marking a development in the art of combined arms operations as follows:

1. Secretly establishing a thorny offensive posture, ensuring that forces of arms can transform posture flexibly. Posture is formed through a wide variety of measures to organise, position, and deploy forces and combat systems in the theatre of war with the aim of creating advantages and bringing into full play combat power of fighting forces. The formation of campaign posture must ensure its suitability for operational concepts because campaign posture always transforms according to specific conditions and circumstances of the theatre. The thornier the posture is, the greater combat power becomes and the better chances for victory the campaign has. In battles involving many arms, close collaboration and coordination among units to set up favourable posture and generate overall strength to annihilate enemy troops are prerequisite, requiring commanders and their staff to secretly set up flexible, thorny posture.

The Campaign Command used the 2nd Division, 36th Regiment, and some artillery, anti-aircraft units of the Military Region to form offensive posture to destroy Nong Son hardened fortification, which had robust firepower and was being defended by the enemy’s regular units. The creativity in establishing posture here is our bold move to deploy artillery in high places, at closer distances to bring into play its fire power and directly shell and destroy 38 out of 41 enemy blockhouses, driving the enemy into panic, thereby allowing the 8th Battalion, 31st Regiment and arms units to annihilate enemy troops inside the base. After the loss of Nong Son, the enemy mounted the military operation code-named “Southern Tsunami” to recapture this area. Having grasped their intention, we deployed the 1st Regiment, 2nd Division at heights such as 136, 238, and 284, Ky Vy, Van Chi, Khuong Que, and Duong Coi to ambush the enemy. The following courses of action took place exactly what the Campaign Command had predicted. The enemy troops fell into our ready-made military posture and the Operation Southern Tsunami ended in a complete failure. As can be seen from the Campaign, the enemy was completely taken by surprise by our placement of artillery at heights, together with their underestimation of our strength to attack and capture complexes of entrenched fortifications such as Nong Son.

Thuong Duc was a strong military division. Therefore, we rearranged forces and combat systems as well as consolidated units’ fortifications, especially those of arms units after two unsuccessful attacks. Accordingly, the 304th Division strengthened its forces, weapons, and strongpoints and reallocated 100mm artillery from the Height 118 to the Height 296, about one kilometer from the enemy position. An anti-aircraft company equipped with 12.7mm machine gun, the 5th Company of the 66th Regiment was sent to Chang Choi and Huu Trinh. The 10th Battalion of Local Force was positioned to the South of River Gia Vu to surround and isolate Thuong Duc. During Thuong Duc battle, on realising that the secondary offensive direction developed well, the Campaign Command timely shifted the secondary offensive direction to the main offensive direction; sited artillery nearer to the enemy to provide direct fire support, making them unable to respond. Thanks to establishment of flexible, thorny offensive posture, our military and people destroyed and captured two bases within one month.

2. Properly using forces and firepower of arms; creatively, flexibly applying types of tactics in operations. In combined arms operations, when combat forces, weapon systems, and equipment are limited, how the troops and firepower of arms are used to make the most of their power is the most important factor. Meanwhile, the use of combat forces and firepower in operations must ensure suitability for specific conditions in the theatre and the enemy. If the enemy forces are in a stable state and organised well, it is essential to concentrate superior force and firepower; make careful preparations; coordinate closely; and mount “sure-to-win” attacks. When the enemy is in the absence of defence and in confusion, there is no need to wait for sufficient concentration of force and firepower. It is necessary to take every opportunity and adopt fighting methods suitable for each arm. More importantly, the creative, flexible employment of tactics and combat methods suitable for strong and weak points of each force is vital for victory in combined arms operations.

In fact, when we launched attacks on Nong Son, the enemy had about two regular battalions and some civil guard units. Nevertheless, the units were densely deployed. Therefore, we used only one battalion to attack this place. Apart from setting up the posture of roadblocks and encirclement and using maneuver warfare, we brought into full play firepower of artillery and air defence systems to provide fire support for the infantrymen. When the enemy launched a counter-attack to recapture Nong Son, we used only one battalion and one engineer company to lure the enemy into our ready-made areas, namely Ky Vy, Van Chi, Khuong Que, Duong Coi, etc., to destroy. Regarding the offensive on Thuong Duc, on realising the motto of “tight encirclement, fierce attack, and complete annihilation within a short period of time,” although the Campaign Command used the 66th Regiment, artillery units, and anti-aircraft units to attack the primary post and the 3rd Regiment to attack peripheral targets, we still succeeded. After that, the Campaign Command timely adjusted forces and combat systems to change from the secondary direction of attack into the primary one, from fierce and swift completion into firm offensive and advance, from maneuver warfare into trench warfare in combination with engaging the enemy dug-in troops, thus overwhelming Thuong Duc military division in a short period of time. When the enemy reinforcements were deployed to recapture Thuong Duc, the Campaign Command ordered units to rush into defence while using the 3rd Regiment, 304th Division to smash the enemy fortifications of Ba Khe, Ban Tan, and Lam Phung along their defensive line, firmly upholding Thuong Duc.

3. Closely coordinating forces of arms and operational areas, leveraging overall strength to attack the enemy. As a result of multiple forces participating in Nong Son – Thuong Duc Campaign, close coordination among units and forces had drawn the attention of the Campaign Command and departments right from the beginning of and during the operation with the aim to bring into play strength of forces and generate overall power to engage the enemy. Accordingly, when attacking Nong Son, the artillery troops provided effective fire support for the 2nd Division to fight the enemy and contributed to destroy 38 out of 41 blockhouses. The engineer troops worked closely with the 2nd Division and local armed forces to establish a thorny posture to be ready to respond to the enemy counter-attacks in Ky Vy, Van Chi, Khuong Que, and Duong Coi. The self-defence force actively fought against A-37s and armed helicopters to protect the 2nd Division. When attacking Thuong Duc, our regular units coordinated with local armed forces to encircle and isolate Thuong Duc. The artillery provided effective fire support for the 304th Division. Consequently, we shot down 13 warplanes, destroyed 3 armoured personnel carriers and many blockhouses. Additionally, the Party Committee of the former Quang Da Special Zone and the 5th Military Region Command directed regular units and local armed forces to strike an ammunition depot at Da Nang airport, and step up offensives in Que Son and Nghia Hanh with the aim of releasing pressure on Nong Son and Thuong Duc, contributing to victory of the Campaign. The Nong Son – Thuong Duc victory broke the outer defensive line of Da Nang joint military base, defeated the enemy’s expansion and stabilisation plan, and created a new position and strength for the 1975 General Offensive and Uprising. Victory of the Campaign marks a new development in the art of combined arms operations and offer many invaluable lessons learnt for the war to safeguard the Fatherland.

Senior Colonel, Dr. PHAM NGOC KHAC, Military History Institute of Viet Nam