The Diem era, 1955–1963

As dictated by the Geneva Conference of 1954, the partition of Vietnam was meant to be only temporary, pending national elections in 1956. Much like Korea, the agreement stipulated that the two military zones were to be separated by a temporary demarcation line (known as the Demilitarized Zone or DMZ). The United States, alone among the great powers, refused to sign the Geneva agreement. The President of South Vietnam, Ngo Dinh Diem, declined to hold elections. This called into question the United States' commitment to democracy in the region, but also raised questions about the legitimacy of any election held in the communist-run North. President Dwight D. Eisenhower expressed U.S. fears when he wrote that "80 per cent of the population would have voted for the Communist Ho Chi Minh."

The cornerstone of U.S. policy was the Domino Theory. This argued that if South Vietnam fell to communist forces, then all of South East Asia would follow. Popularized by the Eisenhower administration, some argued that if communism spread unchecked, it would follow them home by first reaching Hawaii and follow to the West Coast of the United States. It was better, therefore, to fight communism in Asia, rather than on American soil. Thus, the Domino Theory provided a powerful motive for the American creation of a client state in southern Vietnam. The theory underpinned American policy in Vietnam for five presidencies.

The United States pursued a policy of containment. Following the NATO model, Washington established the Southeast Asia Treaty Organization (SEATO) to counter communist expansion in the region. The policy of containment was first suggested by George F. Kennan in the 1947 "X" article, published anonymously in Foreign Affairs. It remained U.S. policy for the next quarter of a century.

Rule

Ngo Dinh Diem was chosen by the U.S. to lead the South Vietnam. A devout Roman Catholic, he was fervently anti-communist and was untainted by any connection to the French. He was one of the few prominent Vietnamese nationalist who could claim both attributes. Historian Luu Doan Huynh notes, however, that "Diem represented narrow and extremist nationalism coupled with autocracy and nepotism."

The new Americans patrons were almost completely ignorant of Vietnamese culture. They knew little of the language or long history of the country. There was a tendency to assign American motives to Vietnamese actions and Diem himself warned that it was an illusion to believe that blindly copying Western methods would solve Vietnamese problems.

In April and June of 1955, Diem (against U.S. advice) cleared the decks of any political opposition by launching military operations against the Cao Dai religious sect, the Buddhist Hoa Hao, and the Binh Xuyen organized crime group (which was allied with members of the secret police and some military elements). Diem accused these groups of harboring Communist agents. As broad based opposition to his harsh tactics mounted, Diem increasingly sought to blame the communists.

Beginning in the summer of 1955, he launched the 'Denounce the Communists' campaign, during which communists and other anti-government elements were arrested, imprisoned, tortured or executed. Opponents were labeled Viet Cong by the regime to demean their nationalist credentials. During this period refugees moved across the demarcation line in both directions. Around 52,000 Vietnamese civilians moved from south to north. 450,000 people, primarily Catholics, traveled from the north to south, in aircraft and ships provided by France and the U.S. CIA propaganda efforts increased the outflow with slogans such as "the Virgin Mary is going South." The northern refugees were meant to give Diem a strong anti-communist constituency.

Main article: 1955 South Vietnamese election

In a referendum on the future of the monarchy, Diem rigged the poll which was supervised by his brother Ngo Dinh Nhu and received "98.2 percent" of the vote, including "133 percent" in Saigon. His American advisers had recommended a more modest winning margin of "60 to 70 percent." Diem, however, viewed the election as a test of authority. On October 26, 1955, Diem declared the new Republic of Vietnam, with himself as president. The creation of the Republic of Vietnam was largely due to the Eisenhower administration's desire for an anti-communist state in the region. Colonel Edward Lansdale, a CIA officer, became an important advisor to the new president.

As a wealthy Catholic, Diem was viewed by many ordinary Vietnamese as part of the old elite that had helped the French rule Vietnam. The majority of Vietnamese people were Buddhist. So his attack on the Buddhist community only served to deepen mistrust. Diem's human rights abuses increasingly alienated the population. As opposition to Diem's rule in South Vietnam grew, a low-level insurgency began to take shape in 1957. Four hundred government officials were assassinated in that year.

In May, Diem undertook a ten day state visit of the U.S. President Eisenhower pledged his continued support. A parade in New York city was held in his honor. Although Diem was openly praised, in private Secretary of State John Foster Dulles conceded that he had been selected because there were no better alternative.

In 1956, one of the leading communists in the south, Lê Duẩn, returned to Hanoi to urge the Vietnam Workers' Party to take a firmer stand on reunification. But Hanoi hesitated in launching a full-scale military struggle, fearing U.S. intervention. Finally, in January 1959, under pressure from southern cadres who were being targeted by Diem's secret police, the north's Central Committee issued a secret resolution authorizing an armed struggle. Diem enacted tough new anti-communist laws. Infiltration of men and weapons from the north began along the Ho Chi Minh Trail.

Observing the increasing unpopularity of the Diem regime, on December 12, 1960, Hanoi authorized the creation of the National Front for the Liberation of South Vietnam (NLF). The NLF was made up of two distinct groups: nationalists and communists. While there were many non-communist members of the NLF, they were subject to party control and increasingly side-lined as the conflict continued. The principle objective of the NLF was to seize political power through a popular insurrection—military operations were secondary. The NLF emphasized patriotism, honesty and good government, while promising the reunification of Vietnam and an end to American influence. Successive American administrations, as Robert McNamara and others have noted, over estimated the control that Hanoi had over the NLF.

John F. Kennedy won the 1960 U.S. presidential election. In his inaugural address, Kennedy made the ambitious pledge to "pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and success of liberty." In May, 1961, Vice-President Lyndon B. Johnson visited Saigon and enthusiastically declared Diem the "Winston Churchill of Asia." Asked why he had made the comment, Johnson replied, "Shit! Diem's the only boy we got out there. " Johnson assured Diem of more aid, in order to mold a fighting force that could resist the communists.

The quality, however, of the South Vietnamese military remained poor. Bad leadership, corruption and political interference all played a part in emasculating the Army of the Republic of Vietnam (ARVN). The frequency of guerrilla attacks rose, as the insurgency gathered steam. Hanoi's support for the NLF played a significant role. But South Vietnamese governmental incompetence was at the core of the crisis. Maxwell Taylor and Walt Rostow recommended that U.S. troops be sent to South Vietnam disguised as flood relief workers. Kennedy rejected idea, but increased military assistance yet again. In April, 1962, John Kenneth Galbraith warned Kennedy of the "danger we shall replace the French as a colonial force in the area and bleed as the French did." By mid-1962, the number of U.S. military advisers in South Vietnam had risen from 700 to 12,000.

On July 23, fourteen nations, including, China, South Vietnam, the Soviet Union, North Vietnam and the United States, signed an agreement guaranteeing the neutrality of Laos.

Coup and assassinations

Some policy-makers in Washington began to conclude that Diem was incapable of defeating the communists and might even make a deal with Ho Chi Minh. He only seemed concerned with fending off coups. As Robert F. Kennedy noted, "Diem wouldn't make even the slightest concessions. He was difficult to reason with …" During the summer of 1963 U.S. officials began discussing the possibility of a regime change. The State Department was generally in favor of encouraging a coup. The Pentagon and CIA were more alert to the destabilizing consequences of such an act, and wanted to continue applying pressure for reforms.

Chief among the proposed changes was the removal of Diem's younger brother Ngo Dinh Nhu. Nhu controlled the secret police and was seen as the man behind the Buddhist repression. As Diem's most powerful adviser, Nhu had become a hated figure in South Vietnam. His continued influence was unacceptable to the Kennedy administration. Eventually, the administration concluded that Diem was unwilling to change.

The CIA was in contact with generals planning to remove Diem. They were told that the United States would support such a move. President Diem was overthrown and executed, along with his brother, on November 2, 1963. When he was informed, Maxwell Taylor remembered that Kennedy "rushed from the room with a look of shock and dismay on his face." He had not approved Diem's murder. The U.S. ambassador to South Vietnam, Henry Cabot Lodge, Jr., invited the coup leaders to the embassy and congratulated them. Ambassador Lodge informed Kennedy that "the prospects now are for a shorter war."

Following the coup chaos ensued. Hanoi took advantage of the situation and increased its support for the insurgents. South Vietnam entered a period of extreme political instability, as one military government replaced another in quick succession. Kennedy increased the number of U.S. military advisers to 16,300 to cope with rising guerrilla activity. They were embedded at every level of the South Vietnamese armed forces. U.S. Army advisers were, however, almost completely ignorant of the political nature of the insurgency. The insurgency was a political power struggle, in which military engagements were not the main goal.

In a conversation with Nobel Peace Prize winner and Canadian Prime Minister Lester B. Pearson, Kennedy sought his advice. "Get out," Pearson replied. "That's a stupid answer," shot back Kennedy. "Everyone knows that. The question is: How do we get out?" Ironically, Kennedy was assassinated on November 22, 1963, just three weeks after Diệm. Kennedy introduced helicopters to the war and created a joint U.S.-South Vietnamese Air Force, staffed with American pilots. He also sent in the Green Berets. He was succeeded by Vice-President Lyndon B. Johnson, who reaffirmed America's support of South Vietnam. By the end of the year Saigon had received $500 million in military aid, much of which was lost to corruption.