Almost ten years to the day after the first US combat troops entered South Vietnam, Communist North Vietnam launched their war winning conventional offensive against South Vietnam.
In 1964, the South Vietnamese Army was almost completely combat ineffective and had to be rebuilt. To buy the time to do so, General William Westmoreland, the commander of the US and SEATO Military Assistance Command- Vietnam (MAC-V), brought in US airpower and US combat troops. Between 1965 and 1968, Westmoreland used US and Allied troops to search for and destroy VC and NVA main force units, while relying on special forces, indigenous militias and the ARVN for counter insurgency and security. These tactics proved effective to a point, but didn’t play well on TV and certainly weren’t quantifiable, though Westmoreland tried with “body counts”. When Westmoreland was denied the authority to cut the Ho Chi Minh Trail and seize communist base camps in the Laotian panhandle and the Fishhook in Cambodia, the war was militarily unwinnable for the US and South Vietnam. North Vietnamese Minister of Defense and commander of the North Vietnamese Army, General Võ Nguyên Giáp, took advantage of this reality and advocated for a slower insurgency campaign that avoided costly big unit engagements. This approach would empower the VC, increase US casualties, embolden the US anti-war movement, and allow time for the Soviet propaganda machine to work over America.
This slower, but inevitably successful, course of action was backed by the Soviet faction inside the North Vietnamese Communist Party, led by Giap and Ho Chi Minh. In 1967, when Ho was ill and Giap at a conference in Moscow, the Chinese faction in the government and armed forces staged a soft coup. The Chinese faction, led by COSVN commander Tran Van Tra and North Vietnamese politician Le Duan, came to power and demanded big unit battle with the Americans, because that was how the French were defeated previously. Returning to Vietnam, Giap was forced to accept the new strategy.
In January 1968, the NVA and VC launched the “General Offensive/General Uprising” i.e. the Tet Offensive, which shocked the Americans and South Vietnamese. However, though the General Offensive portion of the plan was executed, the General Uprising of South Vietnamese was nonexistent. The South Vietnamese populace on the whole refused to support the communists. The NVA and VC were defeated in a few weeks, the VC decisively so. Although the communists suffered extremely heavy casualties, the Tet Offensive turned the US public opinion against the war. The scale of the offensive gave lie to the official Johnson and Westmoreland position that there was a light at the end of the tunnel. Gen Westmoreland was replaced that spring by General Creighton Abrams.
The Tet Offensive destroyed the Viet Cong as a viable military entity, and forced Giap to move NVA regular units into South Vietnam to take their place, setting the insurgency back years. This gave Abrams the opportunity to implement new tactics in Vietnam dubbed the “Inkblot Strategy”. American and ARVN troops secured the cities, town, hamlets, and then the countryside of S. Vietnam through counterinsurgency tactics the way ink blots spread on a piece of paper. Combined with targeted strikes on high value targets and partnering and training of South Vietnamese troops and irregulars, the “inkblot strategy” proved effective. Dubbed “Vietnamization” the strategy was successful, and the ARVN took over security of the country with most American combat troops out of Vietnam by 1972.
Though Abrams’ strategy was successful, the four years of lost time under Westmoreland meant that the South Vietnamese still needed American advisors, air support, supplies, and financial assistance to deal with the increasingly conventional NVA attacks. With American assistance, the ARVN held its own against the NVA coming out of Cambodia and Laos. On New Year’s Eve 1972, Giap conceded that “We have lost the war” (his words) after Operation Linebacker II and the disastrous Easter Offensive, both of which prompted the North Vietnamese to accept the Paris Peace Accords in early 1973. South Vietnam repelled North Vietnam’s 1972, 1973, and 1974 spring offensives, without American combat troops.
As usual for modern American peace deals, the United States kept its part of the bargain and its adversaries did not. In February 1975, the US public was tired of the war. The newly elected Democratic congress cut off all funding to South Vietnam, while North Vietnam was awash in funds and supplies from various Communist bloc countries. On 10 March 1975, Giap launched the spring offensive, named after the deceased former leader of North Vietnam Ho Chi Minh, with hundreds of tanks and artillery pieces. “The Ho Chi Minh Campaign” was the fourth massive conventional spring offensive in as many years against South Vietnam. Giap had reached the bottom of his manpower pool, but unfortunately South Vietnam had neither the resources nor the will to properly defend. The NVA broke through within days and Saigon fell on 30 April.
Contrary to popular historical opinion, South Vietnam did not fall to a popular insurgency, but a conventional attack that would not have been out of place in the Second World War.
130,000 South Vietnamese fled the country and 200,000 more were be murdered by the North Vietnamese over the next month. Hundreds of thousands more were forced into re-education camps. Following their victory in Vietnam, Cambodia fell to the Khmer Rouge, and Laos fell to the Pathet Lao. A further 1.6 million men, women, and children were murdered by the Communists.