Vietnam War

===Ousting and assassination of Ngô Đình Diệm===
{{Main|Cable 243|Arrest and assassination of Ngô Đình Diệm|Buddhist crisis| Krulak Mendenhall mission|McNamara Taylor mission|1963 South Vietnamese coup|Reaction to the 1963 South Vietnamese coup}}
{{See also|Role of the United States in the Vietnam War#John F. Kennedy (1961–1963)|1960 South Vietnamese coup attempt|1962 South Vietnamese Independence Palace bombing|Huế Phật Đản shootings|Xá Lợi Pagoda raids}}

The inept performance of the ARVN was exemplified by failed actions such as the [[Battle of Ap Bac|Battle of Ấp Bắc]] on 2 January 1963, in which a small band of Viet Cong won a battle against a much larger and better-equipped South Vietnamese force, many of whose officers seemed reluctant even to engage in combat.<ref name="Sheehan">{{Cite book |last=Sheehan |first=Neil |title=A Bright Shining Lie – John Paul Vann and the American War in Vietnam |date=1989 |publisher=Vintage |isbn=978-0-679-72414-8|url=https://archive.org/details/brightshininglie0000shee_r0g3}}</ref>{{Rp|201–206}} During the battle the South Vietnamese had lost 83 soldiers and 5 US war helicopters serving to ferry ARVN troops that had been shot down by Vietcong forces, while the Vietcong forces had lost only 18 soldiers. The ARVN forces were led by Diệm's most trusted general, [[Huỳnh Văn Cao]], commander of the [[IV Corps (South Vietnam)|IV Corps]]. Cao was a Catholic who had been promoted due to religion and fidelity rather than skill, and his main job was to preserve his forces to stave off coup attempts; he had earlier vomited during a communist attack. Some policymakers in Washington began to conclude that Diệm was incapable of defeating the communists and might even make a deal with Ho Chi Minh. He seemed concerned only with fending off coups and had become more paranoid after attempts in 1960 and 1962, which he partly attributed to U.S. encouragement. As [[Robert F. Kennedy]] noted, "Diệm wouldn't make even the slightest concessions. He was difficult to reason with{{Nbsp}}..."<ref>Live interview by [[John Bartlow Martin]]. ''Was Kennedy Planning to Pull out of Vietnam?'' New York City. John F. Kennedy Library, 1964, Tape V, Reel 1.</ref> Historian James Gibson summed up the situation:

{{Blockquote|Strategic hamlets had failed{{Nbsp}}... The South Vietnamese regime was incapable of winning the peasantry because of its class base among landlords. Indeed, there was no longer a 'regime' in the sense of a relatively stable political alliance and functioning bureaucracy. Instead, civil government and military operations had virtually ceased. The National Liberation Front had made great progress and was close to declaring provisional revolutionary governments in large areas.<ref>{{Cite news |last=Gibson |first=James |date=1986 |title=The Perfect War: Technowar in Vietnam |page=[https://archive.org/details/perfectwartechno0000gibs/page/88 88] |publisher=The Atlantic Monthly Press |url=https://archive.org/details/perfectwartechno0000gibs |url-access=registration}}</ref>}}

Discontent with Diệm's policies exploded in May 1963, following the [[Huế Phật Đản shootings]] of nine unarmed Buddhists protesting against the ban on displaying the [[Buddhist flag]] on [[Vesak]], the Buddha's birthday. This resulted in mass protests against discriminatory policies that gave privileges to the Catholic Church and its adherents over the Buddhist majority. Diệm's elder brother [[Pierre Martin Ngô Đình Thục|Ngô Đình Thục]] was the Archbishop of Huế and aggressively blurred the separation between church and state. Thuc's anniversary celebrations occurred shortly before Vesak had been bankrolled by the government, and Vatican flags were displayed prominently. There had also been reports of Catholic paramilitaries demolishing Buddhist pagodas throughout Diệm's rule. Diệm refused to make concessions to the Buddhist majority or take responsibility for the deaths. On 21 August 1963, the [[Army of the Republic of Vietnam Special Forces|ARVN Special Forces]] of Colonel [[Lê Quang Tung]], loyal to Diệm's younger brother Ngô Đình Nhu, [[Xá Lợi Pagoda raids|raided pagodas]] across Vietnam, causing widespread damage and destruction and leaving a death toll estimated to range into the hundreds.
[[File:Arvncapture.jpg|thumb|upright|ARVN forces capture a Viet Cong]]

U.S. officials began discussing the possibility of a [[regime change]] during the middle of 1963. The [[United States Department of State]] wanted to encourage a coup, while the Defense Department favored Diệm. Chief among the proposed changes was the removal of Diệm's younger brother Nhu, who controlled the secret police and special forces, and was seen as the man behind the Buddhist repression and more generally the architect of the Ngô family's rule. This proposal was conveyed to the U.S. embassy in Saigon in [[Cable 243]].

The CIA contacted generals planning to remove Diệm and told them that the United States would not oppose such a move nor punish the generals by cutting off aid. President Diệm was overthrown and executed, along with his brother, on 2 November 1963. When Kennedy was informed, Maxwell Taylor remembered that he "rushed from the room with a look of shock and dismay on his face."<ref name=Karnow/>{{Rp|326}} Kennedy had not anticipated Diệm's murder. The U.S. ambassador to South Vietnam, [[Henry Cabot Lodge Jr.|Henry Cabot Lodge]], invited the coup leaders to the embassy and congratulated them. Ambassador Lodge informed Kennedy that "the prospects now are for a shorter war".<ref name=Karnow/>{{Rp|327}} Kennedy wrote Lodge a letter congratulating him for "a fine job".<ref>{{Cite book |title=Foreign Relations of the United States, 1961–1963, Volume IV, Vietnam, August–December 1963 |chapter=304. Telegram From the Department of State to the Embassy in Vietnam—Washington, November 6, 1963—7:50 p.m. |chapter-url=https://history.state.gov/historicaldocuments/frus1961-63v04/d304 |via=Office of the Historian|archiveurl=https://web.archive.org/web/20230404230151/https://history.state.gov/historicaldocuments/frus1961-63v04/d304|archive-date=April 4, 2023}}</ref>

Following the coup, chaos ensued. Hanoi took advantage of the situation and increased its support for the guerrillas. South Vietnam entered a period of extreme political instability, as one military government toppled another in quick succession. Increasingly, each new regime was viewed by the communists as a puppet of the Americans; whatever the failings of Diệm, his credentials as a nationalist (as Robert McNamara later reflected) had been impeccable.<ref name=McNamara/>{{Rp|328}}

U.S. military advisors were embedded at every level of the South Vietnamese armed forces. They were however criticized for ignoring the political nature of the insurgency.{{Sfn|Demma|1989}} The Kennedy administration sought to refocus U.S. efforts on pacification – which in this case was defined as countering the growing threat of insurgency<ref>{{Cite web |date=April 2015 |title=Counterinsurgency in Vietnam: Lessons for Today |url=https://www.afsa.org/counterinsurgency-vietnam-lessons-today |website=The Foreign Service Journal|archiveurl=https://web.archive.org/web/20230407114858/https://afsa.org/counterinsurgency-vietnam-lessons-today|archive-date=April 7, 2023}}</ref><ref>{{Cite web |title=Pacification |url=http://www.vietnamgear.com/dictionary/pacification.aspx |website=Vietnam War Dictionary|archiveurl=https://web.archive.org/web/20230405065336/http://www.vietnamgear.com/dictionary.aspx?s=pacification|archive-date=April 5, 2023}}</ref> – and [[Hearts and Minds (Vietnam War)|"winning over the hearts and minds"]] of the population. The military leadership in Washington, however, was hostile to any role for U.S. advisors other than conventional troop training.<ref>{{Cite book |last=Blaufarb |first=Douglas S. |title=The Counterinsurgency Era: U.S. Doctrine and Performance, 1950 to the Present |date=1977 |publisher=Free Press |isbn=978-0-02-903700-3 |page=119}}</ref> General [[Paul D. Harkins|Paul Harkins]], the [[COMUSMACV|commander of U.S. forces in South Vietnam]], confidently predicted victory by Christmas 1963.<ref name=Herring/>{{Rp|103}} The CIA was less optimistic, however, warning that "the Viet Cong by and large retain de facto control of much of the countryside and have steadily increased the overall intensity of the effort".<ref>{{Cite book |last=Schandler |first=Herbert Y. |url=https://archive.org/details/americainvietnam0000scha |title=America in Vietnam: The War That Couldn't Be Won |date=2009 |publisher=Rowman & Littlefield |isbn=978-0-7425-6697-2 |page=[https://archive.org/details/americainvietnam0000scha/page/36 36] |url-access=registration}}</ref>

Paramilitary officers from the CIA's [[Special Activities Division]] trained and led [[Hmong people|Hmong]] tribesmen in Laos and into Vietnam. The indigenous forces numbered in the tens of thousands and they conducted direct action missions, led by paramilitary officers, against the Communist Pathet Lao forces and their North Vietnamese supporters.<ref>{{Cite book |last1=Southworth |first1=Samuel |url=https://archive.org/details/usspecialforcesg0000sout |title=U.S. Special Forces: A Guide to America's Special Operations Units: the World's Most Elite Fighting Force |last2=Tanner |first2=Stephen |date=2002 |publisher=Da Capo Press |isbn=978-0-306-81165-4 |url-access=registration}}</ref> The CIA also ran the [[Phoenix Program]] and participated in [[Military Assistance Command, Vietnam – Studies and Observations Group]] (MAC-V SOG), which was originally named the Special Operations Group, but was changed for cover purposes.<ref>{{Cite book |last=Warner |first=Roger |title=Shooting at the Moon The story of America's clandestine war in Laos |date=1996 |publisher=Steerforth Press |isbn=978-1-883642-36-5}}</ref>