Communist North & capitalist South (1945–76)
In September 1945, Ho Chi Minh proclaimed the Democratic Republic of Vietnam (DRV) and held the position of Chairman. Communist rule was cut short, however, by nationalist Chinese and British occupation forces whose presence tended to support the Communist Party's political opponents. In 1946, Vietnam had its first National Assembly election (won by the Viet Minh in central and northern Vietnam), which drafted the first constitution, but the situation was still precarious: the French tried to regain power by force; some Cochinchinese politicians formed a seceding government the Republic of Cochinchina while the non-Communist and Communist forces were engaging each other in sporadic battle. Stalinists purged Trotskyists. Religious sects and resistance groups formed their own militias. The Communists eventually suppressed all non-Communist parties but failed to secure a peace deal with France.
Full-scale war broke out between the Việt Minh and France in late 1946 and the First Indochina War officially began. Realizing that colonialism was coming to an end worldwide, France fashioned a semi-independent State of Vietnam, within the French Union, with Bảo Đại as Head of State. France was finally persuaded to relinquish its colonies in Indochina in 1954 when Viet Minh forces defeated the French at Dien Bien Phu. The 1954 Geneva Conference left Vietnam a divided nation, with Hồ Chí Minh's communist DRV government ruling the North from Hanoi and Ngo Dinh Diem's Republic of Vietnam, supported by the United States, ruling the South from Saigon. In the North, the communist government launched a land reform program. It is estimated that some 50,000 people perished in the campaigns against wealthy farmers and landowners. In the South, Diem went about crushing political and religious opposition, imprisoning or killing tens of thousands.
As a result of the Vietnam (Second Indochina) War (1954–75), Viet Cong and regular People's Army of Vietnam (PAVN) forces of the DRV unified the country under communist rule. In this conflict, the North and the Viet Cong—with logistical support from the Soviet Union—defeated the Army of the Republic of Vietnam, which sought to maintain South Vietnamese independence with the support of the U.S. military, whose troop strength peaked at 540,000 during the communist-led Tet Offensive in 1968. The North did not abide by the terms of the 1973 Paris Agreement, which officially settled the war by calling for free elections in the South and peaceful reunification. Two years after the withdrawal of the last U.S. forces in 1973, Saigon, the capital of South Vietnam, fell to the communists, and the South Vietnamese army surrendered in 1975. In 1976, the government of united Vietnam renamed Saigon as Ho Chi Minh City in honor of Ho, who died in 1969. The war left Vietnam devastated, with the total death toll standing at between 800,000 and 3.1 million, and many thousands more crippled by weapons and substances such as napalm and Agent Orange.
Socialist Republic after 1976
In the post-1975 period, it was immediately apparent that the effectiveness of Communist Party (CPV) policies did not necessarily extend to the party's peacetime nation-building plans. Having unified North and South politically, the CPV still had to integrate them socially and economically. In this task, CPV policy makers were confronted with the South's resistance to communist transformation, as well as traditional animosities arising from cultural and historical differences between North and South. Lê Duẩn purged South Vietnamese who had fought against the North, imprisoning over one million people and setting off a mass exodus and humanitarian disaster.
Compounding economic difficulties were new military challenges. In the late 1970s, Cambodia under the Khmer Rouge regime started harassing and raiding Vietnamese villages at the common border. To neutralize the threat, PAVN invaded Cambodia in 1978 and overran its capital of Phnom Penh, driving out the incumbent Khmer Rouge regime. In response, as an action to support the pro-Beijing Khmer Rogue regime, China increased its pressure on Vietnam, and then the Chinese troops crossed Vietnam's northern border in 1979 to "punish" Vietnam as Sino-Vietnamese War, but their foray was quickly pushed back by Vietnamese forces. Relations between the two countries had been deteriorating for some time. Territorial disagreements along the border and in the South China Sea that had remained dormant during the Vietnam War were revived at the war's end, and a postwar campaign engineered by Hanoi against the ethnic Chinese Hoa community elicited a strong protest from Beijing. China was displeased with Vietnam's alliance with the Soviet Union. During its prolonged military occupation of Cambodia in 1979–89, Vietnam's international isolation extended to relations with the United States. The United States, in addition to citing Vietnam's minimal cooperation in accounting for Americans who were missing in action (MIAs) as an obstacle to normal relations, barred normal ties as long as Vietnamese troops occupied Cambodia. Washington also continued to enforce the trade embargo imposed on Hanoi at the conclusion of the war in 1975.
The harsh postwar crackdown on remnants of capitalism in the South led to the collapse of the economy during the 1980s. With the economy in shambles, the communist government altered its course and adopted consensus policies that bridged the divergent views of pragmatists and communist traditionalists. Throughout the 1980s, Vietnam received nearly $3 billion a year in economic and military aid from the Soviet Union and conducted most of its trade with the USSR and other Comecon countries. In 1986, Nguyễn Văn Linh, who was elevated to CPV general secretary the following year, launched a campaign for political and economic renewal (Đổi Mới). His policies were characterized by political and economic experimentation that was similar to simultaneous reform agenda undertaken in the Soviet Union. Reflecting the spirit of political compromise, Vietnam phased out its reeducation effort. The communist gov't stopped promoting agricultural and industrial cooperatives. Farmers were permitted to till private plots alongside state-owned land, and in 1990 the communist gov't passed a law encouraging the establishment of private businesses.