Lyndon Johnson accepted the American commitment to defeat the communist attempt to take over South Vietnam, but he subordinated the implementation of this commitment to the presidential election of 1964 and to his ambitious domestic legislative agenda, which occupied him during the first half of 1965. Consequently, when, in March 1965, he opened direct American participation in  the war, he endeavored to minimize drawing attention to it. The Hanoi govern- ment had been rapidly increasing its military involvement in the south ever since  the death of Ngo Dinh Diem, hoping to gain victory before the US could react. By early 1965, the military position of the Saigon government was deteriorating so quickly that direct American intervention was needed to avoid a debacle. Phan Huy Quat was not enthusiastic about American intervention but had no way of resisting it. The generals understood that American intervention ensured the survival of their armed forces and would fundamentally change the context of Vietnamese politics in their favor. After four months of a US bombing campaign against North Vietnam and of  piecemeal deployments of thousands of American ground troops to South Viet- nam, in July of 1965 Johnson finally announced his policy toward Vietnam. He  proposed an open-ended increase in US troops, the amount to be determined by the number necessary to obtain his aim, which was to persuade Hanoi to abandon its policy of seizing the south. His approach followed a “limited war” theory that had been developed by some academics, which proposed that one could persuade an enemy to renounce its goal through a limited application of military action; it was not necessary to actually force defeat upon an enemy in order to obtain one’s own goal but merely to convince an opponent that it was in its best interest to stop fighting. This theory was combined with the “flexible response” idea that Kennedy had ostensibly embraced to produce the concept of “graduated pressure,” according to which the US would apply increasing levels of military action in Vietnam until Hanoi decided to give up. Ambassador Taylor had argued against the deployment of ground troops, fearing that it would destroy the nationalist credentials of the anti-communist Vietnamese. Johnson replaced him with Lodge, who for the next two years watched from the embassy as more and more American troops arrived. Without a clear strategy for defeating the enemy and gaining victory, American forces concentrated upon logistics, at which they excelled, moving men and material halfway around the world to Vietnam. Westmoreland was tasked with using his  increasing resources to cause maximum battlefield damage to the enemy. Handi- capped by being unable to control the movement of men and materials through  Laos and Cambodia into Vietnam, Westmoreland resorted to a policy of “search and destroy” in which American forces endeavored to locate and apply their superior firepower to communist forces. The result was that communist forces  learned how to be “found” in ways that maximized their advantages and conse- quently they were able to initiate around 80 percent of all combat encounters. It  began to look like a war of attrition by 1966 and 1967. The momentum of American escalation pushed aside the South Vietnamese army and it was relegated to so-called “pacification duties,” dealing with local insurgents and the chaos in civilian life caused by the increase in warfare.  Meanwhile, American forces attempted to engage the units of the North Viet- namese army that increasingly appeared from across the Laotian and Cambo- dian borders. In addition to the land route from North Vietnam through  southern Laos, supplies also reached communist forces by ship to the Cambodian port of Sihanoukville. Sihanouk allowed the movement of military supplies through Cambodia to the Vietnamese border in exchange for a percentage of the shipments. The first major battle between American and North Vietnamese army units occurred in autumn 1965 at what became known as the Battle of Ia Drang, in the Central Highlands near the Cambodian border, in which US airmobile units, recently arrived from the US, endeavored to destroy a large concentration of North Vietnamese soldiers. The North Vietnamese considered the battle a victory because, after inflicting significant casualties upon the Americans, they were able to withdraw in good order across the Cambodian border where they enjoyed immunity from American attack. Although Americans officially claimed the battle as a victory because their casualties were fewer than those of the North Vietnamese, McNamara’s analysis of the battle was the beginning of his doubts about the war. He concluded that the bombing campaign could not sufficiently diminish the movement of men and materials into the south nor could US search and destroy operations disable North Vietnamese units fast enough for any discernible scenario leading to success. Although McNamara persuaded Johnson  to order a brief bombing halt in early 1966 to explore the possibility of negoti- ations, the basic war policy remained unchanged with continued bombing and  ever-increasing numbers of US troops being sent to South Vietnam. By early 1966, the activist monks based in Hue were pressing for the election of a constituent assembly to write a constitution and to re-establish a civilian government. The Americans also endorsed this agenda. Ambassador Lodge, who in 1963 had established a good relationship with Thich Tri Quang, endeavored to keep the Buddhists calm while nudging the Nguyen Cao Ky government in this direction. Complicating this issue was the personal falling out between Nguyen Chanh Thi, who was closely associated with Thich Tri Quang, and the Saigon generals, which exacerbated the alienation of the Buddhist population in the northern part of the country from the government in Saigon. After Nguyen Cao Ky was publicly insulted during a visit to Hue and Da Nang in early March, the Saigon generals decided to relieve Nguyen Chanh Thi of his  command. In response to this, Thich Tri Quang began to broadcast anti- government messages from the Hue radio station and a resistance movement  led by monks and students spread to major cities along the central coast and in the Central Highlands, and also to Saigon. In addition to calling for an end to the military government, the demonstrators also aired anti-American slogans. They  expressed a Buddhist fear that the military government was bringing back offi- cials who had worked for the Ngo Dinh brothers as well as a more general  dismay at the increasing numbers of US combat troops in the country and the expansion of warfare.  During the following three months, two important developments simultan- eously occurred. Soldiers, teachers, students, and others in the Hue–Da Nang  region joined Buddhist activists in resistance against the Saigon government. This  was eventually suppressed by force, and many of the most militantly anti- government people fled to join the communists in the mountains. At the same  time, and to some extent as a political response to the revolt, a committee was formed to draft laws for electing and administering a constituent assembly that would write a constitution. The work of this committee was completed and approved in June 1966, just as the revolt was coming to an end. The election for the constituent assembly was held in September 1966 with 401 candidates standing for 117 seats and around 80 percent of the electorate participating. The election revealed strong regional and sectarian differences. Initially, the largest bloc was mainly comprised of people from north and central Vietnam and included Dai Viet politicians, some Catholics and a few people associated with the military. This bloc was eventually equaled in size by the combination of a Catholic group and a group of southerners led by Hoa Hao leaders that attracted some independents and formed a bloc that supported Nguyen Cao Ky’s efforts to mediate between the assembly and the generals. There was a smaller bloc of militant southern regionalists, an echo of the old Cochinchinese separatist movement of the late 1940s. The Buddhist activists had been discredited by the revolt and consequently there was no significant bloc of people representing their agenda. In October, as the constituent assembly was organizing itself, a crisis erupted when southerners in Nguyen Cao Ky’s cabinet threatened to resign over what they viewed as discriminatory treatment of southerners in favor of northerners. This crisis resonated with the formation of regional blocks in the constituent assembly. Nguyen Cao Ky, a northerner, succeeded in calming the matter and maintaining the unity of his cabinet. He thereafter gave much attention to negotiating compromises between the constituent assembly and the generals. The constitution that was finally completed and approved in March 1967 was the result of significant concessions from both groups. It provided for a strong presidency, a bicameral legislature, and an independent judiciary. After a complex series of procedures and maneuvers in the summer of 1967, eleven men were officially approved to run for president. Although Nguyen Cao Ky was keen to run for president, his military colleagues forced him to run for vice president under Nguyen Van Thieu, who was his senior in rank; the generals feared that without a united military ticket they could lose the election. Of the ten  civilian candidates, Phan Khac Suu and Tran Van Huong were the most prom- inent. Thich Tri Quang called on his followers to boycott the election.  The election was held under the gaze of dozens of American and other international observers. Despite many problems, it was generally evaluated as an accomplishment on the road toward building a democratic political system in wartime. Despite the advantage of holding power, the military ticket received only around 35 percent of the votes. Phan Khac Suu and Tran Van Huong polled well in the cities with each receiving around 10 percent of the votes. Two other candidates received between 5 and 10 percent, and five candidates received less than 5 percent. The surprise of the election was that a man named Truong Dinh Dzu came in second with around 17 percent of the votes. Truong Dinh Dzu (1917–1980s), originally from Binh Dinh Province, studied law in Hanoi and from 1945 practiced law in Saigon. He was rumored to have communist acquaintances, but he also had business relations with people related to Ngo Dinh Diem. He was an active member of the Rotary Club, becoming the  head of the Rotary Club organization in Southeast Asia. He had been investi- gated for bribery, illegally transferring funds abroad, and tax irregularities, but  nevertheless managed to gain approval to run for president. He was an effective speaker and attracted attention with his platform of peace and of negotiation with the communists. He ran well in contested rural areas that were susceptible to communist influence. After the election he was jailed on a currency transaction charge. The Second Republic of Vietnam was inaugurated at the end of October 1967 after completion of National Assembly elections. The government was a civilian–  military hybrid, a structure inhabited by military authority with built-in demo- cratic tendencies that required ongoing negotiation and compromise with civilian  constituents. During the year and a half of preparing and bringing into operation the new constitution, American intervention rose to half a million troops in the country. This dominating American presence had a stabilizing influence on the country’s politics. In 1967, Ellsworth Bunker (1894–1984) was named US ambassador. He was an experienced, competent, and effective career diplomat who, during his six years in Saigon, preserved a predominantly cooperative relationship between the US government and Nguyen Van Thieu. Nguyen Van Thieu’s lack of ability as a political leader was to some extent offset by his caution, his consistency, his mastery of military politics, and his ability to work with Americans. During the four years between the end of the Ngo Dinh regime and the beginning of the Second Republic, the politics of South Vietnam developed amidst an externally supported insurgency and a massive American intervention. A large theme was competition for ascendancy between the two groups that had brought down Ngo Dinh Diem: the Buddhist activists and the military officers. Eventually, the Buddhists were forced to yield. Within the military, a junior cohort relatively susceptible to American influence came to the fore. A large and varied population of civilian politicians, often with strong sectarian and  regional affiliations, actively participated in the many experiments in govern- ment. After a year of negotiation and compromise, a constitutional structure was  adopted that provided a legal framework for politics and administration until dismantled by the communists seven and a half years later.