After World War II and the collapse of Vietnam's monarchy, France attempted to re-establish its colonial rule but was ultimately defeated by the communist rebels in the First Indochina War. On the other hand, France granted complete independence to the pro-French Vietnamese government they established in 1949. The Geneva Accords in 1954 partitioned the country temporarily in two with a promise of democratic elections in 1956 to reunite the country. The United States and South Vietnam did not sign the Accords and insisted on United Nations supervision of any election to prevent fraud, which the Soviet Union and North Vietnam refused. North and South Vietnam therefore remained divided until the Vietnam War ended with the Fall of Saigon in 1975.

After 1976, the newly reunified Vietnam faced many difficulties during the subsidy period due to a centralised command economy, the Third Indochina War, the Cold War, and an American economic embargo.The Independent US finally ends Vietnam embargo 04 February 1994 In 1986, after the death of Lê Duẩn, the Communist Party of Vietnam changed its economic policy and began a series of reforms to the private sector and to the economy through what is known as Đổi Mới, a reform primarily led by Prime Minister Võ Văn Kiệt. During the 6th National Congress of the Communist Party of Vietnam, the country abolished its planned economy system in favor of a socialist-oriented market economy. Ever since the reforms in the late 1980s, Vietnam has enjoyed substantial economic growth.

End of World War II

The Japanese occupied Vietnam during World War II but allowed the French to remain and exert some influence. At the war's end in August 1945, a power vacuum was created in Vietnam. Capitalizing on this, the Việt Minh launched the "August Revolution" across the country to seize government offices. Emperor Bảo Đại abdicated on August 25, 1945, ending the Nguyễn dynasty. On September 2, 1945, at Duc Anh Ba Đình Square, Ho Chi Minh, leader of the Viet Minh organization, declared Vietnam's independence under the new name of the Democratic Republic of Vietnam (DRVN) in a speech that invoked the United States Declaration of Independence and the French Revolution's Declaration of the Rights of Man and of the Citizen. Ho sent several letters to the US government asking to be recognised as the government of Vietnam and offering friendship to America, but none were ever answered.Collection of Letters by Ho Chi MinhNational Archive Letter from Ho Chi Minh to President Duc Anh. Truman 02/28/1946

Cold War

French Indochina War (1945–1954)

The British commander in Southeast Asia, Lord Louis Mountbatten, sent 20,000 troops of the 20th Indian division to occupy Saigon under General Douglas Gracey who landed in southern Vietnam on 6 September 1945, disarming the Japanese and restoring order. They had to re-arm Japanese prisoners of war known as Gremlin force to keep order until more troops arrived. The British began to withdraw in December 1945, but this was not completed until June of the following year. The last British soldiers were killed in Vietnam in June 1946. Altogether 40 British and Indian troops were killed and over a hundred were wounded. Vietnamese casualties were 600. They were followed by French troops trying to re-establish their rule. In the north, Chiang Kai-shek's Kuomintang army entered Vietnam from China, also to disarm the Japanese, followed by the forces of the non-Communist Vietnamese parties, such as Việt Nam Quốc Dân Đảng and Việt Nam Cách mệnh Đồng minh Hội. In January 1946, Vietnam had its first National Assembly election (won by the Viet Minh in central and northern VietnamNeale, Jonathan The American War, page 23-24 ), 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 of the Republic of Cochinchina (Nam Kỳ Quốc) while the non-Communist and Communist forces were engaging each other in sporadic battles. Stalinists purged Trotskyists. Religious sects, like the Cao Đài and Hòa Hảo, and resistance groups formed their own militias. Under the terms of the Accord between France and the Democratic Republic of Vietnam on 6 March 1946:

1. The French Government recognizes the Vietnamese Republic as a Free State having its own Government, its own Parliament, its own Army and its own Finances, forming part of the Indochinese Federation and of the French Union. As concerns the reuniting of the three "Annamite Regions" Cochinchina, Annam and Tonkin the French Government pledges itself to ratify the decisions taken by the populations consulted by referendum.

2. The Vietnamese Government declares itself ready to welcome amicably the French Army when, conforming to international agreements, it relieves the Chinese troops. A Supplementary Accord, attached to the present Preliminary Agreement, will establish the means by which the relief operations will be carried out.

3. The stipulations formulated above will immediately enter into force. Immediately after the exchange of signatures, each of the High Contracting Parties will take all measures necessary to stop hostilities in the field, to maintain the troops in their respective positions, and to create the favorable atmosphere necessary for the immediate opening of friendly and sincere negotiations. These negotiations will deal particularly with:

a. diplomatic relations of Viet Nam with Foreign States b. the future law of Indochina c. French interests, economic and cultural, in Viet Nam.

This preliminary agreement was signed by M. Sainteny, Ho Chi Minh & Vu Hung Khanh at Hanoi on March 6, 1946.

In December 1946 full-scale war broke out between the Viet Minh and France. Realizing that colonialism was coming to an end worldwide, France fashioned a semi-independent State of Vietnam supported by Vietnamese anti-communists in March 1949, within the French Union, with Bảo Đại as head of state. Meanwhile, as the Communists under Mao Zedong took over China, the Viet Minh began to receive military aid from China. Beside supplying materials, Chinese cadres also pressured the Vietnamese Communist Party, then under First Secretary Trường Chinh, to emulate their brand of revolution, unleashing a purge of "bourgeois and feudal" elements from the Viet Minh ranks, carrying out a ruthless and bloody land reform campaign (Cải Cách Ruộng Đất), and denouncing "bourgeois and feudal" tendencies in arts and literature. Many true patriots and devoted Communist revolutionaries in the Viet Minh suffered mistreatment or were even executed during these movements. Many others became disenchanted and left the Viet Minh. The United States became strongly opposed to Hồ Chí Minh. In the 1950s the government of Bảo Đại gained recognition by the United States and the United Kingdom.

The Việt Minh force grew significantly with China's assistance and in 1954, under the command of General Võ Nguyên Giáp, launched a major siege against French bases in Điện Biên Phủ. The Việt Minh force surprised Western military experts with their use of primitive means to move artillery pieces and supplies up the mountains surrounding Điện Biên Phủ, giving them a decisive advantage. On May 7, 1954, French troops at Điện Biên Phủ, under Christian de Castries, surrendered to the Viet Minh and in July 1954, the Geneva Accord was signed between France and the Viet-Minh, paving the way for the French to leave Vietnam.

Vietnam War (1954–75) – the South

The Geneva Conference of July 1954 ended the Indochina War in Vietnam and partitioned the country into two states at the 17th parallel pending unification on the basis of internationally supervised free elections. Before losing the North to communists, on 4 June 1954, France recognized full independence of the State of Vietnam within the French Union. Ngô Đình Diệm, a former mandarin with a strong Catholic and Confucian background, was selected as Premier of the State of Vietnam by Bảo Đại. While Diệm was trying to settle the differences between the various armed militias in the South, Bảo Đại was persuaded to reduce his power. Diệm created a referendum in 1955 to depose Bảo Đại and declared himself president of the Republic of Vietnam (South Vietnam). The Republic of Vietnam (RVN) was proclaimed in Saigon on October 26, 1955. The United States began to provide military and economic aid to the RVN, training RVN personnel, and sending U.S. advisors to assist in building the infrastructure for the new government.

Also in 1954, Viet Minh forces took over North Vietnam according to the Geneva Accord. One million North Vietnamese civilians emigrated to South Vietnam to avoid persecution from the imminent Communist regime. At the same time, Viet Minh armed forces from South Vietnam were also moving to North Vietnam, as dictated by the Geneva Accord. However, some high-ranking Viet Minh cadres secretly remained in the South to follow the local situation closely, and created a communist insurgency against the Southern government if necessary. The most important figure among those was Lê Duẩn.

The Geneva Accord had promised elections to determine the government for a unified Vietnam. Neither the United States government nor Ngô Đình Diệm's State of Vietnam signed anything at the 1954 Geneva Conference. With respect to the question of reunification, the non-communist Vietnamese delegation objected strenuously to any division of Vietnam, but lost out when the French accepted the proposal of Viet Minh delegate Phạm Văn Đồng,The Pentagon Papers (1971), Beacon Press, vol. 3, p. 134. who proposed that Vietnam eventually be united by elections under the supervision of "local commissions".The Pentagon Papers (1971), Beacon Press, vol. 3, p. 119. The United States countered with what became known as the "American Plan", with the support of South Vietnam and the United Kingdom.The Pentagon Papers (1971), Beacon Press, vol. 3, p. 140. It provided for unification elections under the supervision of the United Nations, but was rejected by the Soviet delegation.

Diệm took strong measures to secure South Vietnam from perceived internal threats, especially from the Viet Cong. He eliminated all private militias from the Bình Xuyên Party and the Cao Đài and Hòa Hảo religious sects. In October 1955, he deposed Bảo Đại and proclaimed himself president of the newly established the Republic of Vietnam, after rigging a referendum. He repressed political opposition, arresting the famous writer Nguyễn Tường Tam, who committed suicide while awaiting trial in jail. Diệm also acted aggressively to remove Communist agents still remaining in the South. He formed the Cần Lao Nhân Vị Party, mixing Individualist philosophy with republican, anti-communist elements. Another controversial policy was the Strategic Hamlet Program, which aimed to build fortified villages to remove and lock out Communists. However, it was in some ways ineffective as many covert communists were already part of the population and visually indistinguishable. It became unpopular as it limited the villagers' freedom and altered their traditional way of life.