During the Cold War in the 1960s, the United States and South Vietnam began a period of gradual escalation and direct intervention referred to as the "Americanization" of joint warfare in South Vietnam during the Vietnam War. At the start of the decade, United States aid to South Vietnam consisted largely of supplies with approximately 900 military observers and trainers. After the assassinations of both Ngô Đình Diệm and John F. Kennedy in November 1963 and the Gulf of Tonkin incident in mid-1964, and amid continuing political instability in the South, the Lyndon Johnson Administration made a policy commitment to safeguard the South Vietnamese regime directly. The American military forces and other anti-communist SEATO countries increased their support, sending large scale combat forces into South Vietnam; at its height in 1969, slightly more than 400,000 American troops were deployed. The People's Army of Vietnam (PAVN, often termed the North Vietnamese Army or NVA by the U.S.) and the allied Viet Cong (VC) fought back, keeping to countryside strongholds while the anti-communist allied forces tended to control the cities. The most notable conflict of this era was the 1968 Tet Offensive, a widespread campaign by the communist forces to attack across all of South Vietnam; while the offensive was largely repelled, it was a strategic success in seeding doubt as to the long-term viability of the South Vietnamese state. This phase of the war lasted until after the January 1969 inauguration of Richard Nixon and the change of U.S. policy to Vietnamization, thus ending the direct involvement of U.S. combat troops via phased withdrawal and giving the main combat role back to the South Vietnamese military.
One of the main problems that the joint forces faced was continuing weakness in the South Vietnamese government, along with a perceived lack of stature among the generals who rose up to lead it after the original government of Diem was deposed., pp. 10–18 Coups in 1963, January 1964, September 1964, December 1964, and 1965 all shook faith in the government and reduced the trust of civilians. According to General Trần Văn Trà, the [North Vietnamese] Party concluded, the "United States was forced to introduce its own troops because it was losing the war. It had lost the political game in Vietnam.", pp. 38–40 Robert McNamara suggests that the overthrow of Dương Văn Minh by Nguyễn Khánh, in January 1964, reflected differing U.S. and Vietnamese priorities.
And since we still did not recognize the North Vietnamese and Vietcong as nationalist in nature, we never realized that encouraging public identification between Khanh and the U.S. may have only reinforced in the minds of many Vietnamese that his government drew its support not from the people, but from the United States., p. 112
Frustrations and overthrow of Diem
The situation in South Vietnam continued to deteriorate with corruption rife throughout the Diem government and the ARVN unable to effectively combat the Viet Cong. In 1961, the newly elected Kennedy Administration promised more aid and additional money, weapons, and supplies were sent with little effect. Some policy-makers in Washington began to believe that Diem was incapable of defeating the communists, and some even feared that he might make a deal with Ho Chi Minh. Discussions then began in Washington regarding the need to force a regime change in Saigon. This was accomplished on 1 November 1963, when the CIA aided a group of ARVN officers to overthrow Diem. To help deal with the post-coup chaos, Kennedy increased the number of US advisors in South Vietnam to 16,000.
LBJ's war begins
Johnson approval of covert operations OPPLAN 34A was finalized around 20 December, under joint MACV-CIA leadership; the subsequent MACV-SOG organization had not yet been created. There were five broad categories, to be planned in three periods of 4 months each, over a year:Shultz, pp. 38–39
Clandestine human-source and signals intelligence collection from locations in the north Psychological operations against the north to increase tension and division; Colby had already started such operations Paramilitary operations, such as raids and sabotage against facilities that were significant to the admittedly weak economy, and stronger security, of North Vietnam Encouraging the development of an underground resistance movement Selected raids as well as reconnaissance to direct air strikes, with more of a tactical goal than the economic and security actions of category
Lyndon Johnson agreed with the idea, but was cautious. He created an interdepartmental review committee, under Major General Victor Krulak, on 21 December, to select the least risky operations on 21 December, which delivered a report on 2 January 1964, for the first operational phase to begin on 1 February.
North Vietnam decides on intensification INR determined that the North Vietnamese had, in December, adopted a more aggressive stance toward the South, which was in keeping with Chinese policy. This tended to be confirmed with more military action and less desire to negotiate in February and March 1964, pp. 29–30 Historian William J. Duiker has seen the political dynamics of this time as putting Lê Duẩn in charge and Ho becoming a figurehead.William J. Duiker, Ho Chi Minh: A Life (2001), pp 534–37 online; Ilya Gaiduk, Confronting Vietnam: Soviet Policy toward the Indochina Conflict, F1954-1963 (2003) online pp 203–4
PAVN Colonel Bùi Tín led a reconnaissance mission of specialists reporting directly to the Politburo, who said, in a 1981 interview with Stanley Karnow, that he saw the only choice was escalation including the use of conventional troops, capitalizing on the unrest and inefficiency from the series of coups in the South. The Politburo ordered infrastructure improvements to start in 1964.Shultz, pp. 45–46
Late 1963 to 1964 (before Gulf of Tonkin incident) In February and March 1964, confirming the December decision, there was more emphasis on military action and less attention to negotiation.INR-IV, pp. 29–31 As opposed to many analysts who believed the North was simply unaware of McNamara's "signaling"; INR thought that the North was concerned of undefined U.S. action on the North and sought Chinese support. If INR's analysis is correct, the very signals mentioned in the March 1965 John McNaughton memo, which was very much concerned with Chinese involvement, may have brought it closer.
There were numerous ARVN and VC raids, of battalion size, for which only RVN losses or body count is available. They took place roughly monthly. In the great casualty lists of a war, 100–300 casualties may not seem an immense number, but these have to be considered as happening at least once a month, with a population of perhaps 10 million. It was a grinding war of attrition, with no decision, as death and destruction ground along.
For example, on 23 March 1964, ARVN forces in Operation Phuong Hoang 13-14/10, Dien Phong Sector, raids a VC battalion in a fortified village, killing 126. On 13 April, however, the VC overran Kien Long (near U Minh Forest), killing 300 ARVN and 200 civilians.
Command changes and continued actions On 25 April, General William Westmoreland was named to replace General Paul D. Harkins; an ARVN ambush near Plei Ta Nag killed 84 VC.
Ambassador Henry Cabot Lodge Jr. resigned on 23 June, with General Maxwell D. Taylor named to replace him. In the next two days, the ARVN would succeed with Operation Thang Lang-Hai Yen 79 on the Dinh Tuong–Kien Phuong Sector border, killing 99 VC, followed the next day by an attack on a training camp in Quảng Ngãi, killing 50. These successes, however, were offset by the Buddhist crisis and the increased instability of Diem's regime.
Post-Diem activity After Diem's fall in November 1963, INR saw the priority during this period as more a matter of establishing a viable, sustainable political structure for South Vietnam, rather than radically improving the short-term security situation. It saw the Minh-Tho government as enjoying an initial period of popular support as it removed some of the most disliked aspects of the Diem government. During this time, the increase in VC attacks was largely coincidental; they were resulting from the VC having reached a level of offensive capability rather than capitalizing on the overthrow of Diem.
During this period, INR observed, in a 23 December paper, the U.S. needed to reexamine its strategy focused on the Strategic Hamlet Program, since it was getting much more accurate – if pessimistic – from the new government than it had from Diem. Secretary McNamara, however, testified to the House Armed Service Committee, on 27 December, that only a maximum effort of American power could salvage the situation. Two days later, the Minh Tho government was overthrown. , pp. 10–12
North Vietnamese buildup PAVN Colonel Đồng Sĩ Nguyên brought in battalions of engineers to improve the Trail, principally in Laos, with up-to-date Soviet and Chinese construction equipment, with a goal, over several years, of building a supply route that could pass 10 to 20,000 soldiers per month. At this time, the U.S. had little intelligence collection capability to detect the start of this project. MACV-SOG under its first commander, Colonel Clyde Russell, was specifically prohibited from any operations in Laos, although SOG was eventually authorized to make cross-border operations.
U.S. and GVN covert action planning and preparation
Before the operations scheduled by the Krulak committee could be attempted, there had to be an organization to carry them out. An obscure group called MACV-SOG appeared on the organization charts. Its overt name was "MACV Studies and Operations Group". In reality, it was the Special Operations Group, with CIA agent programs for the North gradually moving under MACV control – although SOG almost always had a CIA officer in its third-ranking position, the second-in-command being an Air Force officer. The U.S. had a shortage of covert operators with Asian experience in general. Ironically, Assistant Secretary of State Roger Hilsman, who had been a guerrilla in Asia during the Second World War, was forced out of office on 24 February.Major General John K. Singlaub, the third commander of SOG, argued that special operators needed to form their own identity: today's United States Special Operations Command has components from all the services, with a regional Special Operations Component, alongside Army, Navy, Air Force, and Marine Components, in every geographic Unified Combatant Command. Post-Vietnam, officers from the special operations community have risen to four-star rank, including Chairman of the Joint Chiefs of Staff, but during the Vietnam War special operators were regarded as outcasts, unlikely to rise high in rank.Shultz, pp. 46–48
To understand factors that contributed to the heightened readiness in the Gulf, it must be understood that MACV-SOG OPPLAN 34A naval operations had been striking the coast in the days immediately before the incident, and at least some North Vietnamese naval patrols were deployed against these.
Possible consequences of such actions, although not explicitly addressing the OPPLAN34A operations, were assessed by the United States Intelligence Community in late May, on the assumption: