On November 1, 1963, President Ngô Đình Diệm and the Personalist Labor Revolutionary Party of the Republic of Vietnam (South Vietnam) were deposed by a group of CIA-backed Army of the Republic of Vietnam officers who disagreed with Diệm's handling of the Buddhist crisis and the North Vietnamese-Viet Cong (VC) threat to South Vietnam. During South Vietnam's later years, some referred to the coup as Cách mạng 1-11-1963 (The 1st November 1963 Revolution).
The Kennedy administration had been aware of the coup planning, but Cable 243 from the United States Department of State to U.S. Ambassador to South Vietnam Henry Cabot Lodge Jr. stated that it was U.S. policy not to try to stop it. Lucien Conein, the Central Intelligence Agency's liaison between the U.S. Embassy and the coup planners, told them that the U.S. would not intervene to stop it. Conein also provided 3 million Vietnamese piastres (approx. $42,000 USD) to reward military units that joined the coup. The decision to support the coup stemmed from the Kennedy administration's growing conviction that Diem was incapable of uniting the South Vietnamese people against communism. Diem's government was also increasingly seen as repressive, particularly after his violent crackdown on Buddhist protests.
The coup was led by General Dương Văn Minh and started on 1 November 1963. It proceeded smoothly, for many loyalist leaders were captured after being caught off-guard, and casualties were light. Diệm was captured and assassinated the next day, along with his brother and advisor Ngô Đình Nhu.
Background
Diệm's road to political power began on 16 June 1954, when former emperor Bảo Đại, serving as Head of State, appointed him Prime Minister of the State of Vietnam in recognition of his strong anti-communist and anti-colonialist stance. He accepted the position of Prime Minister because on June 4th, France had recognized the complete independence of the State of Vietnam.
The two, however, became embroiled in a power struggle after Vietnam was divided in July. The issue was brought to a head when Diệm scheduled a referendum for October 1955, which was rigged by his brother Nhu, and proclaimed himself the President of the newly created Republic of Vietnam. He proceeded to strengthen his autocratic and nepotistic rule over the country. A rubber-stamp legislature wrote a constitution that gave Diệm the power to create laws by decree and arbitrarily give himself emergency powers. Dissidents, both communist and nationalist, were jailed and executed in the thousands, and elections were routinely rigged. Opposition candidates were threatened with being charged for conspiring with the North Vietnamese People's Army of Vietnam, which carried the death penalty, and in many areas, large numbers of Army of the Republic of Vietnam (ARVN) troops were sent to stuff ballot boxes. Diệm kept the control of the nation firmly within the hands of his family, and promotions in the ARVN were given on the basis of loyalty rather than merit. Two unsuccessful attempts were made to depose Diệm; in 1960, a paratrooper revolt was quashed after Diệm stalled for negotiations to buy time for loyalists to put down the coup attempt, while a 1962 palace bombing by two Republic of Vietnam Air Force (RVNAF) pilots failed to kill him.
By 1963, many but not the majority of Buddhists in South Vietnam had grown resentful of Diệm's perceived favoritism toward Catholics. Allegedly, public servants had been promoted on the basis of religious preference, and government contracts, land, and business favors were preferentially given to Catholics. The Catholic Church was the largest landowner in the country, and its holdings were exempt from land reform (i.e., appropriation). In the countryside, Catholics were de facto exempt from performing corvée labor. In 1957, Diệm dedicated the nation to the Virgin Mary.
Discontent with Diệm and Nhu exploded into mass protest during mid-1963 when nine Buddhists died at the hand of Diệm's army and police on Vesak, the birthday of Gautama Buddha. In response, the US government was concerned that it might be "impossible for the Diem/Nhu government to succeed and for us [the United States] to continue to support them". The response by Ambassador Frederick Nolting was, "We should take it slow and easy and see if we can live with the Diem government." As a result of this potential inability to support the Diem/Nhu government, the United States government discussed a proposed coup. In a telegram to the American Embassy in Saigon, U.S. Assistant Secretary of State Roger Hilsman says that at some point, were the US to require "political liquidation" in South Vietnam, it should also "urgently examine all possible alternative leadership and make detailed plans as to how we might bring about Diem's replacement if this should become necessary". In May 1963, a law against the flying of religious flags was selectively enforced; the Buddhist flag was banned from display on Vesak, while the Vatican flag was displayed to celebrate the anniversary of the consecration of Archbishop Pierre Martin Ngô Đình Thục, Diệm's brother. Many Buddhists defied the ban and a protest was ended when government forces opened fire. With Diệm remaining intransigent in the face of escalating Buddhist demands for religious equality, sections of society began calling for his removal from power.
The key turning point came shortly after midnight on 21 August, when Nhu's ARVN Special Forces raided and vandalized Buddhist pagodas across the country, arresting thousands of monks and causing a death toll estimated to be in the hundreds. Numerous coup plans had been explored by the army before, but the plotters intensified their activities with increased confidence after the administration of US President John F. Kennedy authorized the US embassy to explore the possibility of a leadership change through Cable 243. They felt Diệm's policies were making their allied regime in Vietnam politically unsustainable.
Conspiracies
There were many conspiracies against Diệm in 1963, many by different cliques of military officers independent from one another. According to the historian Ellen Hammer, there were "perhaps as many as six and possibly more" different plots, and these spanned the gamut of society to include civilian politicians, union leaders, and university students.
Plotting by mid-level officers
In mid-1963, one group was composed of mid-level officers such as colonels, majors, and captains. Colonel Đỗ Mậu, director of military security, was in this group, which was coordinated by Trần Kim Tuyến, South Vietnam's director of intelligence. Tuyến had been a palace insider, but a rift had developed in recent years, and he began plotting as early as 1962. As South Vietnam was a police state, Tuyến was a powerful figure and had many contacts. Another person in this group was Colonel Phạm Ngọc Thảo, an undetected communist agent who was deliberately fomenting infighting among the officers and mismanaging the Strategic Hamlet Program in order to destabilise the Saigon government.
Tuyến's group had many officers who were members of the opposition Việt Nam Quốc Dân Đảng and Đại Việt Quốc Dân Đảng, who had been discriminated against on issues of promotions, which were preferentially given to members of the regime's Cần Lao Party, a secret Catholic organisation responsible for maintaining Diệm's grip on power. These officers included commanders of airborne, marine and tank units from the 5th Division, mostly at battalion level.
When Tuyến's machinations were uncovered, he was exiled by Nhu. Mậu and Thảo took over but their initial coup plans for 15 July were shelved when American CIA officer Lucien Conein instructed Thảo's superior, General Trần Thiện Khiêm, the head of the ARVN, to stop the coup on the grounds that it was premature. Thảo and Mậu's group resumed plotting, intending to move on 24 October and they recruited a total of 3000 men. They augmented their forces with an assortment of officers from auxiliary units such as from the Signal Corps, Transportation Corps and some RVNAF pilots. Mậu enlisted the help of Khiêm following Tuyến's departure into exile. Mậu gained the cooperation of an assortment of military and civilian dissidents known as the Military and Civilian Front for the Revolution in Vietnam (MCFRV). The MCFRV had started to plot independently in August and their leader was a cousin of Mậu.
Thảo's 24 October coup was canceled after senior officers decided that their younger colleagues could not succeed without the help of General Tôn Thất Đính, a loyalist who controlled the III Corps. The generals sabotaged the younger officers by ordering one of their key regiments into the countryside to fight the communists. The younger officers' plot was integrated into the generals' larger group, and because Khiêm and Mậu were involved with both groups.
After the coup was completed, the media learned that the conspiracy organised by Tuyến and Thảo had been more advanced than that of the generals' before the latter were integrated into the main plot. General Trần Văn Đôn threatened to have the younger officers arrested but Mậu intervened to protect them.
Plotting by the generals
Following the Xá Lợi Pagoda raids, the senior generals started their own plot in earnest, having only had vague plans prior to this. General Đôn, nominally a high-ranking general, but in a position without command of troops since the palace distrusted him, was sought out by Mậu, who wanted to collaborate. Mậu later accompanied the ranking general in the plot, Dương Văn Minh, on recruitment campaigns. Despite his high rank, Minh was out of favour and served as the Presidential Military Advisor, a meaningless desk job where he had no subordinates in the field and no access to soldiers. Mậu helped Minh to secure the cooperation of General Nguyễn Khánh, who commanded the II Corps that oversaw the Central Highlands of the country, and Colonel Nguyễn Văn Thiệu, who commanded the 5th Division based just outside the capital in Biên Hòa. According to Thiệu, Mậu and Minh had promised to establish a more strongly anti-communist government and to keep Diệm as a figurehead president.
Recruitment of Đính
The generals knew that without the cooperation of General Đính, a coup would be difficult as his III Corps forces oversaw the region surrounding the capital. Regarded by his peers as ambitious, vain and impulsive, Đính was a favorite of the Ngô family, and headed the military wing of the Cần Lao Party. Đính converted to Catholicism as Diệm trusted his co-religionists and promoted officers based on loyalty and not competence. Đính was known mainly for his drunken presence in Saigon's nightclubs, and the CIA labeled him a "basic opportunist".
Đính privately claimed responsibility for the pagoda attacks, stating to a journalist, "I have defeated Henry Cabot Lodge [the US ambassador to South Vietnam]. He came here to stage a coup d'état, but I, Tôn Thất Đính, have conquered him and saved the country." During this period, Đính claimed he was "a great national hero". His ego had been played upon by the Ngô brothers, who reiterated this point and paid him a large cash bonus after the pagoda raids. In the heady times after the attacks, Đính told his American advisors that "he was without doubt the greatest general officer in the ARVN, the saviour of Saigon ... and soon he would be the top military man in the country".
In a press conference soon after, Đính claimed to have saved South Vietnam from "foreign adventurers", a euphemism for the United States. After being questioned sharply, Đính quickly became angry. Ray Herndon of United Press International (UPI) asked him to name the country that he was referring to, but Đính dodged the question. Herndon lampooned him by saying that a national hero should be able to identify the national enemy, and asked him to call Madame Nhu, the country's First Lady known for her anti-American comments, to get help in identifying the hostile country in question. After several reporters derisively laughed at his comments, Đính angrily stormed out of the conference hurling vulgarities at the newsmen in both English and Vietnamese.
Đính returned to the officers' mess at the Joint General Staff (JGS) headquarters and his colleagues attempted to play on Đính's ego to convince him to join their plot. In a series of meetings, the other generals assured Đính that he was a national hero worthy of political authority, and claimed that Nhu had not realised how important he was in the future of the country. Đính's colleagues even bribed his soothsayer to predict his elevation to political power. The other generals told him that the people were dissatisfied with Diệm's cabinet and that Vietnam needed dynamic young officers in politics, and that their presence would reverse the declining morale in the ARVN. They advised Đính to ask Diệm to promote him to Interior Minister, Dương Văn Minh to Defence Minister, and Trần Văn Minh to Education Minister.