The Vietnamese–American relationship unraveled in 1963 as a result of several factors. The flawed Laotian agreement of 1962 facilitated North Vietnamese use of southern Laos to supply communist forces in South Vietnam. This assisted Hanoi’s response to the challenge of strategic hamlets and of escalating American advisory, logistical, and air support activities. Harriman, the chief architect of the Laos agreement, bitterly resented Ngo Dinh Diem’s criticism of it. Harriman was the most influential among a group of officials in the State Department and the National Security Council that pressed for Ngo Dinh Diem’s removal from power. These officials were emboldened when he began to appear increasingly vulnerable during the course of 1963. This vulnerability developed from at least five sources: French foreign policy, which aimed to extend to South Vietnam the neutralization scheme that had been imposed on Laos; disenchanted erstwhile American supporters; the response of American public opinion to critical news reports from Saigon; a movement to overthrow him led by Buddhist monks; and military officers susceptible to signs of American encouragement for them to organize a coup. President de Gaulle imagined a role for France in Southeast Asia as the patron of neutral countries who desired to avoid the bipolar Cold War alternatives. Norodom Sihanouk (1922–2012), the leader of Cambodia, was an enthusiastic supporter of this, and the Laotian agreement of 1962 appeared to offer an example of power sharing between communists and non-communists. The Hanoi government professed to see benefit in this French initiative. In the south, some Vietnamese saw it as a way to avoid war and to reverse the tide of American advisors. Officially, the Saigon government and the US considered neutralism as simply a step toward surrender. However, as the Ngo Dinh brothers became increasingly alienated from the Americans during 1963, this path out of the American shadow acquired some plausibility, and rumors of contact between the two Vietnamese governments added to the rising tension between Saigon and Washington, DC.  In 1961, some American academics who had participated in an aid and advis- ory program in Vietnam sponsored by Michigan State University published  articles denouncing Ngo Dinh Diem as a dictator. With the dramatic escalation of American assistance to Saigon during 1962, a dissenting view that American aid was being wasted on behalf of an unworthy tyrant gained traction among some American intellectuals. The most influential of these critics was Michael Joseph Mansfield (1903–2001), a former Professor of Latin American and Far Eastern History who in 1961 became the majority leader of the US Senate. Mansfield was a senior member of Kennedy’s political party who, like Kennedy, had voiced strong support for Ngo Dinh Diem in the 1950s. However, after a visit to Saigon in late 1962, he advised Kennedy that Ngo Dinh Diem was unworthy of continued American assistance. Mansfield was widely respected for his expertise on Asia and for his thoughtful, considered manner. The official report of his trip to Vietnam was published in February 1963. It asserted that continued support of the Saigon government was a waste, and it recommended that the US should withdraw from the Vietnamese situation. The Mansfield report raised doubts about Vietnamese policy in the minds of some American politicians and officials, and it damaged Ngo Dinh Diem’s confidence in the future of Vietnamese–American relations. Meanwhile, a group of young American reporters had become advocates of overthrowing the Ngo Dinh brothers. In January 1963, a small battle in which communist forces inflicted disproportionate damage on South Vietnamese forces was reported from the vantage of an American advisor who had participated in the battle and who blamed its outcome on the corruption and incompetence of the Vietnamese government. This battle, which the Americans called the Battle of Ap Bac, was not representative of military activity in the country at that time, but it was reported in American newspapers as a major defeat for Saigon, a turning point in favor of the communists, and an indictment of Vietnamese leadership. Reports of this event in the US cast doubt on the efficacy of American efforts in Vietnam so long as the Ngo Dinh brothers remained in power. Despite the negativity generated against the Ngo Dinh brothers in the American press and among American officials, Kennedy remained confident in McNamara’s positive evaluation of progress on the battlefield and in the importance of Ngo Dinh Diem for maintaining political stability in Saigon. This changed with the eruption of the Buddhist movement in the summer of 1963. Although the Ngo Dinh brothers had successfully asserted their ascendancy over the religious sects in the Mekong River plain and over rival urban-based political parties such as the Nationalists and the Dai Viet, and although they had shown an ability to compete with communists for control of the rural population, they were relatively oblivious to the vulnerability created by their adherence to Roman Catholicism, and particularly to how this vulnerability was exacerbated by Ngo Dinh Thuc (1897–1984), the eldest living brother who, after serving more than twenty years as a bishop at Vinh Long in the Mekong plain, had been appointed Archbishop of Hue in late 1960. The great infusion of Catholic refugees from northern Vietnam in 1954, added to southern Catholics, was a ready source of support for the Ngo Dinh brothers, who tended to rely upon Catholics not only because of their relatively high level of education, economic prowess, and community discipline, but also because of the role of the Church in recommending and guaranteeing the behavior of loyal people. Catholic refugees contributed to the larger tension between northerners and southerners, between immigrants benefiting from government assistance and local inhabitants struggling for a livelihood. But beyond this, many southerners converted to Catholicism as a step closer to the center of power, and advantages gained thereby were resented and viewed as discriminatory by those who chose not to take that path.  Ngo Dinh Diem had no discernible intention to discriminate against non- Catholics, and he labored to establish good relations with the Buddhist monkhood. He subsidized the building and repair of Buddhist temples and guaranteed freedom of religion. Yet, the undercurrent of incipient favoritism toward Catholics remained. This may never have broken into the open as it did in 1963 without the destabilizing activities of Ngo Dinh Thuc as Archbishop of Hue, for Hue also happened to be the center of a Buddhist leadership disposed to challenge Ngo Dinh Diem on both religious and political grounds. Ever since the “Buddhist revival” led by Vien Chieu in the 1920s and 1930s, there was a strong tendency toward radical political activism among some Buddhist monks with nationalist inclinations. By the 1940s, Vien Chieu and others had gone so far as to leave the monkhood and to join the Indochinese Communist Party. In the early 1950s, many young Vietnamese circulated between the monkhood and the Viet Minh struggle against French colonialism. After 1954, some monks continued to maintain contact with one another across the demilitarized zone. In the early 1960s, many monks supported the idea of neutralism as a way to avoid civil war. In their opinion, the Ngo Dinh regime discriminated against Buddhists in favor of Catholics and had furthermore  opened the country to American domination and civil war. The Kennedy admin- istration’s military escalation produced a sense of urgency among monks to stop  the slide into a war. Young Vietnamese monks were encouraged to take an active part in public affairs by the larger movement of Asian Buddhists that had arisen in the 1950s from nationalist struggles against colonialism and in reaction to the Cold War clash of non-Asian ideologies. This was in contrast to older, more conservative, monks who tended to be based in rural areas and who preferred to avoid the vicissitudes of politics. Hue was a former royal capital and colonial cultural center. Monks there tended to be politically alert with a sense of responsibility for the country. Until the appointment of Ngo Dinh Thuc as Archbishop of Hue, Ngo Dinh Can (1911–1964), a younger Ngo Dinh brother, had effectively governed the northern part of South Vietnam and maintained good relations with the local Buddhist monks, including Thich Tri Quang (b. 1924), a leader among the younger, more politically inclined monks based at Hue. However, Ngo Dinh Thuc overshadowed his younger brother and destabilized the situation by mixing  his efforts to promote Catholicism with his influence over government adminis- tration. He demonstrated a high-profile arrogance and insensitivity toward non- Catholics that alienated many Buddhists from the Saigon government. Buddhist  leaders accused him of aggressive proselytizing with the weight of the govern- ment behind him. Ngo Dinh Diem could not bring himself to acknowledge that  his elder brother, to whom he had given respect and deference throughout his life, was creating a problem. In early May 1963, uproar broke out in Hue over the discriminatory enforce- ment of regulations about the flying of religious flags. The twenty-fifth anniver- sary observance of Ngo Dinh Thuc’s ordination as a bishop had flourished  Catholic flags, but shortly after this some local officials tried to prevent the flying of Buddhist flags during the observance of Vesakha, commonly referred to in English as Vesak or “the Buddha’s birthday.” Vesak was a relatively new Buddhist holiday that had been established in 1950 at the inaugural conference of the World Fellowship of Buddhists in Colombo, Sri Lanka, which thereafter encouraged the promotion of Buddhism in national cultures. Thich Tri Quang had studied in Sri Lanka and became active in the Vietnam General Buddhist Association that was founded in 1951 by monks who were inspired by the Colombo meeting. After 1954, this organization was abolished in North Vietnam when the communist authorities implemented a policy to control and discourage religion, but it continued to exist in South Vietnam, based at Hue, where by 1963 Thich Tri Quang had become one of its leaders. A French colonial law that permitted the term “church” to be used only by Catholics had produced the term “association” in the organization’s name. That this law had never been revoked is an indication of Ngo Dinh Diem’s lack of awareness or concern about the resentment it produced and about the danger of allowing his elder brother to flaunt Catholicism in the region most committed to a Buddhist version of nationalism. Thich Tri Quang was prominent in organizing the 1963 Vesak observance as a response to Ngo Dinh Thuc’s activities. He was determined to use the occasion to rally public resentment against the archbishop and against the official policy of discrimination that the archbishop seemed to promote. Although government officials quickly disowned and reversed the effort to prevent display of Buddhist flags, Thich Tri Quang and his followers aroused a campaign of protest against religious discrimination of which the flag controversy was symbolic. Thich Tri Quang led a demonstration to the Hue radio station with the intention of broadcasting his complaints against the government. After soldiers arrived on the scene, explosions killed several demonstrators. According to various theories, the soldiers, or the communists, or even the Americans had set off the explosions, but evidence for assigning culpability remains inconclusive and controversial. Nevertheless, Thich Tri Quang took the most plausible and expedient line of blaming the government, which was widely believed. He presented the government with five demands: freedom to fly Buddhist flags, revocation of the law forbidding Buddhist organizations the legal status of a “church,” indemnification for the families of those who died at the radio station, punishment of those responsible for the deaths, and the end of all discrimination against Buddhists. Ngo Dinh Diem was slow to respond to these demands. He was reluctant to acknowledge any official policy of religious discrimination, and he blamed the radio station deaths on the communists. He preferred to deal with older, less radical monks, but did not arrive at an agreement with them until mid June, by  which time Thich Tri Quang and his activist followers had expanded their anti- government activities to Saigon and staged the public immolation of a monk to  protest what was reported in the American press as “religious persecution.” This event provoked widespread outrage against Ngo Dinh Diem’s government in the US and turned the Kennedy administration against him. Kennedy replaced Nolting with Henry Cabot Lodge, Jr. (1902–1985), a former senator, ambassador to the UN, and candidate for vice president who came from a social background similar to Kennedy and Harriman and who shared Harriman’s disdain for uncooperative leaders of client states. By the time Lodge arrived in Saigon in August, the Vietnamese government had ended a summer of Buddhist street demonstrations by declaring martial law, seizing temples, and removing activist monks to prison or to the custody of senior monks in rural areas. Thich Tri Quang took refuge in the US embassy where Lodge treated him as an honored guest and where he acknowledged that his aim was to bring down the government. Buddhists and foreign newsmen charged that the suppression of the Buddhist movement during the raids on temples had been excessively violent and that many people had been killed. Ngo Dinh Diem subsequently requested and obtained a UN “fact-finding team” that arrived in October and was permitted to investigate without restrictions. The UN report, made public after Ngo Dinh Diem’s downfall, claimed that there had been no deaths and that those imprisoned had all been released. Meanwhile, Ngo Dinh Diem held elections for the National Assembly that had been scheduled at the end of August but were postponed due to the imposition of martial law. Martial law was lifted in mid September and the election was held at the end of the month. This was the most open and least manipulated national election held under Ngo Dinh Diem. The number of elected members affiliated with the National Revolutionary Movement that served as the front organization  for the Ngo Dinh brothers fell from seventy-six to fifty-five while those unaffili- ated with the regime increased from thirty-six to sixty-six. Ngo Dinh Diem  accepted the election results and opened the new, albeit relatively powerless, legislature shortly before his death. By this time, US policymakers were no longer interested in electoral reform, having already decided the fate of Ngo Dinh Diem’s regime. In late August, Lodge endeavored to promote a military coup against Ngo Dinh Diem in response to instructions from the State Department drafted by Harriman and his collaborators, which Kennedy subsequently approved. The senior generals on whom the Americans began to place their hopes had begun their careers with the French army; some had been French citizens. The leading figure among them was Duong Van Minh (1916–2001), the son of a wealthy Cochinchina landowner whom Ngo Dinh Diem had retired from active service. The catalyst for the flurry of plotting in late August was the arrival of Lodge and his clandestine contacts with disgruntled officers. On the other hand, Harkins made no secret of his lack of enthusiasm for a coup, which, along with a lack of mutual trust among the generals, initially stymied efforts to organize a conspiracy. In July, at the peak of the Buddhist demonstrations, Ngo Dinh Diem staged trials of civilians who had been arrested in connection with the coup attempt of  November 1960, and other former political figures were summoned for ques- tioning as well. This was a warning to aspiring politicians tempted to support  Thich Tri Quang’s call for a change of government. Ngo Dinh Diem had excluded from his government people associated with the Nationalist and Dai Viet Parties, ostensibly because of their past status as clients of China and Japan and their participation in Bao Dai’s governments in the early 1950s. They also represented rival networks of men with political and administrative experience. In February 1962, two air force pilots had bombed the presidential mansion; one of them was the son of a Nationalist Party leader who had been briefly jailed in 1960. The plotting military officers had no ability to govern, but there were many doctors, lawyers, former administrators, and other professional people who were alienated from the Ngo Dinh regime and were ready to serve if given an opportunity. During September and October 1963, Kennedy leaned toward the State Department view of Ngo Dinh Diem and waited on Lodge’s efforts to encourage the generals to seize the government. The plotters asked that the Commodity Import Program be suspended as a signal that the US government fully supported them; this was done in mid October. After a final face-to-face meeting between Lodge and one of the generals to convey assurance that the US approved the conspiracy, Ngo Dinh Diem and Ngo Dinh Nhu were seized and killed at the beginning of November. Ngo Dinh Thuc was out of the country at the time and never returned. Ngo Dinh Can was killed six months later. The overthrow of  Ngo Dinh Diem was Kennedy’s most fateful achievement in Vietnam. It funda- mentally changed the Vietnamese–American relationship and set US involvement  in Vietnam in a new direction. Ngo Dinh Diem had stabilized a government in South Vietnam that resisted Hanoi’s efforts to destroy it by means of political agitation, terrorism, and  insurgency. His strength lay in the desire of various groups to maintain a non- communist option for the future of the country, in his reputation as a nationalist, and in his ability to elicit American aid. However, when Hanoi resorted to military means to overthrow his government in 1959, each of these strengths became a weakness. His strict attitude toward national sovereignty, a vestige of his disgust with French colonialism, also extended toward critics and potential allies, and he withdrew into the inner circle of his family and personal entourage. The widespread desire for an effective anti-communist leader had benefited him in the mid 1950s, but he alienated many public-spirited people who were disappointed at being denied an opportunity to contribute to national affairs. His blindness to the seriousness of his elder brother stirring up religious resentment in the northern part of the country made him vulnerable to both his Vietnamese and his American critics. Increasingly  concerned about the double threat of communist insurgency and American intru- sion, he allowed the monk-led demonstrations against his government to continue  for nearly four months, undermining his control of the military and his relationship  with the United States. American support became the poison he feared; it over- whelmed and finally discarded him. Without American encouragement, the army  generals would never have moved against him. The generals were united not so much against Ngo Dinh Diem as by the opportunity offered by the Americans.