Northeastern Cambodia Counter-offensive Campaign (February 2nd - May 31st 1971)

PANO – In early 1971, employing "war of strangulation", the US and vassal forces started to expand the war by launching operations in Laos and Cambodia theatres aiming at disrupting the transport route and the immediate strategic rear of the Vietnamese forces. Employing 88 out of 214 infantry battalions, 15 armored combat units, the enemy launched a large-scale offensive in three directions: the "Lam Son 719 Operation" attacking the area of Route 9 - Southern Laos, the "Final Victory (Toan Thang) Operation 1-71 NB" covering the northeastern Cambodia, and North Kon Tum operation attacking the border T-junction (Attapeu, Southern Laos).

Technical staff and soldiers of Artillery Regiment 368 fixing weapon during Route 9 – South Laos Campaign (Photo: Archived photo)

During the "Final Victory (Toan Thang) Operation 1-71 NB", the enemy hit the Kratic area, Road 7, Dam He, and Suong Chup of Kampong Cham in the Northeast of Cambodia with the ambition to surround and destroy major part of the regular forces, the headquarters, and stores, and prevent the advance of the Liberation Army of the South. The operation was also to ease the pressure on Military Region 1 of Cambodia so as to pacify the East of Highway 1 and Highway 7, seeking a military victory in order to reassure their henchmen in Phnom Penh. The force mobilized consisted of three infantry divisions (divisions 3, 18, 25), Cavalry Brigade 3, Special Task Force Combat Unit 3, the naval task force, 12 artillery battalions (216 105mm and 175mm artillery guns), three armored units of over 400 tanks and armored vehicles and powerful US air support. In addition, five infantry battalions of the Lol Nol Cambodian government (pro-US forces) were also mobilized.

On the Vietnamese side, at the end of 1970, in the liberated areas of Cambodia, the force started building the army rear, overcame difficulties in infrastructure to maintain the smooth transportation along the Truong Son - Ho Chi Minh Trail and largely completed the logistics system. Particularly, in Cambodia theatre, we continued to expand the liberated land to rural areas, cutting the traffic system to form the siege around Phnom Penh and isolate the Lol Nol force. In 1971, learning that the enemy was opening large-scale military operations in the Northeast of Cambodia, the Southern Military Party Committee and Command decided to launch a counter-offensive campaign to defeat the enemy, helping promote the revolution in the South and Cambodia to a new height, protecting our stores and transportation trail.

Vietnamese force joining the campaign consisted of three infantry divisions (divisions 5, 7, 9), two artillery regiments (75, 96), a commando regiment, an engineer regiment, three independent companies of three bases (bases 10, 20, 30). Southern Commander Tran Van Tra directly commanded the campaign. Equivalent to an army corps level, the campaign took place fiercely, lasting from February 4^th to May 31^st 1971, divided into three stages:

Stage 1, from February 4^th to March 4^th 1971.

The enemy conducted rapid attacks, capturing Suong Chup, penetrating deep into Dam Be - So Heng area. Vietnamese forces preemptively counter-attacked the enemy in separated areas of individual divisions, concentrating forces to break the primary attack direction of the enemy, forcing the enemy to retreat to Road 7. The combat intention, plan and offensive of the enemy were initially changed.

Stage 2, from March 5^th to April 16^th 1971.

The Vietnamese side concentrated force to break two operations of Combat Unit 48 and and Brigade 3 of the enemy. Promoting the victory, we moved on, conducting offensive, pushing back the enemy to Can Dan and Cho Rum, completely destroying Combat Unit 48, Brigade 3, and Combat Unit 5. The divisions, then, maneuvered to three areas of Chup, Mi Mot, and So Nun, ready to counter-attack new operations of the enemy.

Stage 3, from April 17^th to June 24^th 1971.

Knowing that Vietnamese forces were preparing for new combat activities, the enemy has actively conducted preventive measures by maneuvering forces, aircraft, artillery guns and assistance, and sending the special task force to survey Vietnamese preparation. Under pressure, Combat Unit 8 in So Nun and Lol Nol forces on the east bank of the Tonlé Sap River were forced to send for reinforcement forces. Vietnamese forces then destroyed the reinforcements and prevented the enemy from capture Suong Chu north of Road 7.

From May 25^th, Vietnamese forces encircled and laid pressure on Combat Unit 8 and other neighboring units, cutting off all the communications, food and water supplies, and traffic to the enemy, wearing out the enemy’s morale, tightening the siege around Combat Unit 8, attacking Cavalry Brigade 3 of the enemy.

On May 30^th, Brigade 3 of the enemy suffered from heavy losses while Combat Unit 8 was forced to retreat. Vietnamese forces tightened the siege and destroyed Combat Unit 8. Saigon Army Corps 3 forces were all disrupted and destroyed while supporting Brigade 3 and Combat Unit 8. The enemy suffered from heavy losses, retreating to form defensive line. Vietnamese forces pursued the enemy forces and ended the campaign while Infantry Division 9 continued attacking the enemy along Road 7.

After 3 months of brave and wise combat, Vietnamese forces ended the campaign in victory, destroying 25,000 troops, the whole Combat Unit 8, a tank regiment, 18 infantry battalions, an artillery battalion, six armored companies, two tank companies, 1,509 military vehicles (639 armored vehicles, 167 105mm artillery guns, 34 other military vehicles, etc), shooting down 238 aircraft, defeating the operations in the dry season of 1970 - 1971 of the enemy, firmly safeguarding the immediate rear of the southern theatre.

The Northeastern Cambodia Counter-offensive Campaign failed the "Final Victory (Toan Thang) Operation 1-71 NB" of the US and Saigon government forces. Along with the victory of the Route 9 - Southern Laos Campaign, the victory of the Northeastern Cambodia Campaign sped up the collapse of the Saigon government, dealing a great blow to the "Vietnamization" strategy of the US forces and the plot to use Saigon army instead of American troops as the key force in South Vietnam, Laos, and Cambodia theatres.

The campaign also marked the maturity of the regular forces of the Liberation Army in terms of the organization and command of campaigns at army corps level in more difficult conditions. The highlight of the art of campaign operations is the timely direction and properly assessment of the enemy intentions, on which we built full plans and effectively organized preparation. During the campaign, Vietnamese force took the initiative in actively attacking right from the beginning.

Written by Nguyen Ngoc Toan

Translated by Huu Duong