By 1968, 535,000 US troops had been sent to South Vietnam. Although the US Army favoured fighting conventional ‘big unit’ battles against the enemy, they were forced to adapt their tactics due to the strengths and strategy of their enemy, and political limits imposed in Washington.
Two factors contributed to the evolution of the US military strategy in Vietnam. First, Johnson insisted that no ground operations could take place outside of South Vietnam, and second the nature of the enemy. While the US believed that the Democratic Republic of Vietnam (DRV) was responsible for the insurgency in the South, the actual fighting would be carried out principally against the Viet Cong: an enemy which was elusive as it was determined to dictate the nature and timings of confrontation.
Breaking with the orthodox objective of seizing territory, the US tried to break the will of the Communist forces by killing so many of their soldiers that that they would eventually give up. Secretary of Defense, Robert McNamara insisted that a crossover point would be reached when the DRV would be unable to replace its forces as quickly as they were being killed off. As a result, an attritional strategy was developed with the object of killing as many element combatants as possible.
Soldier from A Company, 1st Air Cavalry Division, checking houses a during patrol, 10 June 1966
NARA
‘Search and Destroy’ was, therefore, an ad hoc tactical innovation created to implement the attritional strategy in Vietnam. It relied on the premise that US technology coupled with aggressive ground patrolling, would be able to find the Viet Cong and North Vietnamese Army (NVA) main force units. Then US firepower would be able to inflict such casualties that the enemy would be unable to sustain the war.
The tactic has been criticized from different angles. Some historians claim that it placed too much emphasis on a military solution to the conflict, at the expense of attempts to win the ‘hearts and minds’ of the South Vietnamese people. Already suspicious of foreign interference within their country, their support for the US was undermined by the growing number who became refugees, and the extent to which South Vietnam was bombed by the US, in a relatively fruitless attempt to interdict the supply of men and material into the country. There were also US atrocities such as My Lai, where between 300–500 unarmed men, women, children and babies were murdered by three US platoons in March 1968.
The military bristled at the President’s refusal to extend the war to Laos and Cambodia, and the restrictions imposed on bombing and troop levels. This led several senior military figures, such as William Westmoreland, to claim US armed forces had to fight in Vietnam with one hand tied behind their back. After the Tet Offensive, Westmoreland requested an injection of 206,000 more troops, claiming that the NVA had suffered a significant military loss and could be finished off with one last push. Indeed in 1976, he claimed that Johnson’s refusal to provide these troops was the ‘turning point of failure’.
From a strategic point of view, the tactic appeared to make little sense. With the emphasis placed on the body count, rather than on securing and consolidating territory, US troops frequently participated in intense battles only to vacate the land to the enemy shortly afterwards. Perhaps the most controversial illustration of this tactical flaw was the ten-day assault on Hamburger Hill in May 1969. After suffering over 340 casualties during the battle US troops left the hill on 5 June. Soon after this battle, President Nixon announced the first stages of US withdrawal from Vietnam. US strategy changed in other ways under Nixon. While attempting to achieve a breakthrough at the negotiating table, he sought to undermine the enemy’s war effort by hunting down bases in Cambodia and Laos, and by escalating the bombing campaign. The secret US invasion of Cambodia in 1970 was intended to find the main NVA command structure, but was brought to a premature end when details of the operation became public. The following year, US forces supported an ARVN incursion into Laos, which ended in an embarrassing retreat by the South Vietnamese Army.
The main US bombing campaign was Rolling Thunder: a strategic–interdiction campaign designed to convince the North Vietnamese that they could not win. This objective was to be achieved through graduated and increasingly intense bombing strikes upon military and logistics targets in North Vietnam. The White House maintained strict control over the nature of targets. Decisions as routine as the choice of ordnance for a particular sortie were made at presidential level, thousands of miles away from the fighting. Johnson also insisted on sporadic halts in the bombing campaign in order to give Hanoi time to reflect on its continuing support for the Viet Cong in the South. As with the ground war, the failings of the air campaign were apparent from an early stage. From a practical perspective, the goal of interdicting supplies from the North failed largely because the DRV industrial base was the USSR, its satellites and China. Supplies were dispatched overland through China, through DRV ports, and through the Cambodian port of Sihanoukville.
The military argued that Johnson should have sanctioned an unlimited bombing campaign against the North, instead of restricting targets, and imposing unnecessary rules of engagement. They point to the success of Operation Linebacker II in 1972, a hugely destructive example of ‘unlimited’ warfare, which forced the DRV to sign the Paris Peace Accords in January 1973. If this tactic had been pursued from 1965, they argue the war could have ended on terms more favourable to the US.
In the most basic sense, the US bombing campaign 1965–68 reflected an inability to identify the enemy’s real vulnerabilities. The majority of the targets on the initial list were eventually hit over the three-and-a-half years leading to Rolling Thunder’s inauspicious culmination, with little impact upon the outcome of the conflict. Much of the North’s military output was produced in China or shipped in from the Eastern Bloc. As neither Johnson nor Nixon was prepared to bomb China or mine Haiphong Harbour (something Nixon didn’t do until 1972), there was little hope of destroying the North’s capacity to wage war.