During the American war in Vietnam, in addition to testing and using modern weapons based on the advantages of aircraft, tanks and armor, the United States deployed high technology with the ambition to Take the initiative on the battlefield, typically the McNamara Electronic Fence.

In the mid-1960s, although the US military's bombing missions against the North and Truong Son road to prevent reinforcements from the North to the South were carried out on a large scale, the effectiveness of the attacks was poor. inversely proportional to the volume of bombs and ammunition used. Bombing did not reduce the ability to provide aid from the North to the South but also cost the US billions of dollars. In that context, in 1966, the US government organized a research group of 47 scientists with modern military techniques to find new solutions. After three months of work, a project to build a defensive line along the demilitarized zone using the most modern weapons and military technical equipment of the US military at that time was born. Accordingly, the fence will consist of two parts: one part aimed at pedestrians and one part aimed at motor vehicles. The location chosen to build the anti-pedestrian fence is the southern flank of the demilitarized zone (DMZ) to the Laos border and then north to Se Pon, through the periphery of Muong Xen, all about 100km long. about 20km wide. The anti-vehicle system includes acoustic detectors that are continuously monitored by patrol aircraft. The cost of such a system is estimated at $800 million per year. According to this calculation, once the fence was established, all supplies to the South would become meaningless.

The author of the electronic fence bearing his own name once confidently commented, “At first, the fence may not be completely effective, but I believe that it can take effect in time and then, fundamentally, It can increase our advantage in terms of the purpose of the war. It will hinder the enemy, will permit more effective use of the limited number of standing troops, and will be convincing evidence that our sole purpose is to protect the South from invasion from the South. North"

Since 1966, the McNamara electronic fence was built with the purpose of preventing the North's reinforcements from entering the South. The McNamara electronic fence combined with the air force is responsible for detecting and bombing to immediately destroy every group of people, every vehicle, every cannon, every package brought from the North to the South. The fence includes 17 military base systems, combined with a dense obstacle system, modern ground and aerial electronic reconnaissance equipment arranged continuously in an area about 100km long and 100km wide. 10-20km from Cua Viet port to Route 9 to the Vietnam - Laos border. At the same time, the US army and the Republic of Vietnam maintain a fairly strong defense force here to control the line around the clock. In addition to the infantry force, there are also strong artillery and armored forces. Fighter and attack aircraft continuously hovered, ready to destroy all targets that crossed the defense line. B52 strategic bombers are also ready for raiding operations.

However, on the Truong Son route, in January 1968, the amount of supplies for the Southern battlefield doubled compared to December 1967, the number of troops en route to the South amounted to 45,00 people along with some gas. Large assets such as 85mm, 122mm guns and tanks were also brought safely into the South. With that reinforcement, the attack on the Khe Sanh stronghold group and especially the 1968 Mau Than General Offensive and Uprising by the Vietnamese army and people proved that the McNamara electronic fence had failed.

To learn more about the McNamara electronic fence, you can read the book "The High-Tech War at the McNamara Electronic Fence (1966-1972)" by Associate Professor, PhD. Hoang Chi Hieu is currently stored at the War Remnants Museum Library.