After the signing of the Paris Peace Accords — which Thiệu opposed — and the American withdrawal, South Vietnam resisted the communists for another two years until the communists ’ final final push for victory, which saw the South openly invaded by the entire North Vietnamese Army.

This allowed the communists to generate much momentum and within a month they were close to Saigon, prompting Thiệu to resign and leave the country aboard an American helicopter, just before the communists completed their conquest.

Thiệu later became known for his paranoia and distrust of his American allies when he rose to the top of politics.

Thiệu was quoted in a Central Intelligence Agency ( CIA ) report as being described by an unnamed American official as “ intelligent, highly ambitious, and likely to remain a coup plotter with the aim of personal advancement ”.

In late 1973, the communists issued Resolution 21, which called for “ strategic raids ” against South Vietnam to gain territory and to gauge the reaction of Thiệu and the American government.

General Creighton Abrams, the head of American forces in Vietnam, recommended Trưởng to President Nguyễn Văn Thiệu, saying, " I can recommend, without any reservations at all … Trưởng.

In 1967, a transition to elected government was scheduled ; and, after a power struggle within the military, Thiệu ran for the presidency with Kỳ as his running mate — both men had wanted the top job.

Many senior officers, in particular the Catholics, such as Khiêm and Thiệu, decried what they viewed as a handing of power to the Buddhist leaders, They then tried to remove Khánh in favour of Minh, and recruited many officers into their plot.

In 1966, with Kỳ leading the way, Thi was sacked in a power struggle, provoking widespread civil unrest in his base in I Corps ; Quang led Buddhist protests against Kỳ and Thiệu and many units in I Corps began disobeying orders, siding with Thi and the Buddhist movement.

Thiệu was intent on concentrating power into his own hands.

Thiệu used the period to consolidate his personal power.

Thiệu saw an opportunity to consolidate his personal power and he took it.

In August 1964, after Khánh decided to take more power for himself by declaring a state of emergency and introducing a new constitution, Buddhists launched protests against the new junta, claiming that there was a plot to revive the Diêm era by predominantly Catholic groups such as Cần Lao veterans and Đại Việt supporters, pinpointing Khiêm and Thiệu, both Catholics who had been favoured by Diêm.

However, he had little power as Thiệu operated what was virtually a one-man rule.

Despite this, Thiệu agreed to join the coup against Diệm in November 1963 in the midst of the Buddhist crisis, leading the siege on Gia Long Palace.

Thiệu started as the commander of an infantry platoon fighting against the Việt Minh.

Thiệu turned against Diệm late, and led his 5th Division in the revolt.

He had desired that General Thi, known for his pro-Buddhist position, would lead the country, and denounced Thiệu for alleged past crimes against Buddhists.

Thiệu expressed his stance on the ceasefire by publicly proclaiming the “ Four Nos ”: no negotiations with the communists ; no communist political activities south of the Demilitarized Zone ( DMZ ); no coalition government ; and no surrender of territory to the North Vietnamese or Provisional Revolutionary Government ( PRG ), which went against the deal.

In April, Thiệu launched the Svay Rieng Campaign against communist strongholds in eastern Cambodia near Tây Ninh, in what was the last major ARVN offensive.

Its troops had brought along a tape recording of Hồ Chi Minh announcing the liberation of Saigon and calling for a " General Uprising " against the Thiệu government.

General Trưởng held communist forces at bay before Huế and then launched ( against the initial resistance of President Nguyễn Văn Thiệu and MACV ) Operation Lam Son 72.

Crown Prince Hồng Bảo became the leader of a rebellion against Tự Đức, consisting of Confucian scholars who were angered that the family hierarchy had been dishonored ( by passing over the eldest son ) some remaining supporters of the Lê Dynasty ( who many still considered the legitimate dynasty of Vietnam ) as well as the usual peasants angry over Nguyễn taxation and the usual corrupt mandarins as well as the Roman Catholic missionaries and Christian converts who had been so persecuted by Minh Mạng and Thiệu Trị.

In 1968, he was caught out by the Tết Offensive due to complacency, and during the 1971 Operation Lam Sơn 719 and the communists ’ Easter Offensive, the I Corps in the north of the country was under the command of his confidant, Hoàng Xuân Lãm, whose incompetence led to heavy defeats until Thiệu finally replaced him with Ngô Quang Trưởng.

Kỳ and Thiệu were more concerned with attacking the communists than their predecessors.

During the Lunar New Year of 1968, the communists launched a massive attack on the cities of Vietnam in an attempt to topple Thiệu and reunify the country under their rule.

" Lyndon Johnson's unilateral decision on 31 March to curtail the bombing of North Vietnam only confirmed what Thiệu already feared, that the Americans were going to abandon South Vietnam to the communists.

With no support or leadership from Thiệu, the evacuation turned into a costly debacle, as the communists pounded the city with artillery, killing tens of thousands of people.

In 1971, Minh claimed that Thiệu had caused the deaths by hesitating and delaying the attack on Gia Long Palace, implying that if Diệm was captured there, junior officers could not have killed him while in a small group.

This prompted U. S. Ambassador Maxwell D. Taylor to angrily berate Thiệu, Thi, Kỳ and Cang in a private meeting and threaten to cut off aid if they did not reverse their decision.

Trưởng requested permission to withdraw his forces into the three enclaves as planned ; Thiệu ordered him to " hold onto any territory he could with whatever forces he now had, including the Marine Division ", implying that he could retreat if needed.

At first the Việt Minh retreated into Thiệu ’ s old family home, confident that he would not attack his own house, but they were mistaken.

U. S. Embassy logs during the coup claimed that Thiệu and Khiêm “ seem so passive that they appear to have been either tacitly supporting or associated with his move by Đức and Phát ”.

Thiệu took a cautious approach, as did Có and Cang, and they were pre-empted by Colonel Phạm Ngọc Thảo, an undetected communist double agent, who launched a coup with Phát on a hardline Catholic platform without U. S. backing.

In 1971, Thiệu ran for re-election, but his reputation for corruption made his political opponents believe the poll would be rigged, and they declined to run.

Khiêm's lack of public action was seen as tacit support for the coup ; A U. S. Embassy log during the coup claimed that the Thiệu and Khiêm " seem so passive that they appear to have been either tacitly supporting or associated with his move by Đức and Phát ", and that Khiêm had " issued expressions of firm support for Khánh somewhat belatedly ", as control was eventually reestablished.

Diệm was captured and executed and Thiệu made a general.

President Thiệu made a nationwide radio broadcast that afternoon proclaiming that Huế would be held " at all costs ", contradicting the previous order.

In October 1965 the junta of Kỳ and Thiệu made Khiêm the Ambassador to Taiwan ; he served there until mid-1968, then returned to Vietnam and served under President Thiệu as Interior Minister for a year before becoming Deputy Prime Minister at the start of 1969.

Khiêm and Thiệu sought out U. S. Ambassador Maxwell Taylor and sought a private endorsement for a coup, but Taylor did not want any more changes in leadership, fearing a corrosive effect on the already unstable government.

The only obstacle to a settlement then became Nguyễn Văn Thiệu, whose government would have to assent to any agreement.