Just as the
First Indochina War—which emerged from the complex situation following World War II—and the Vietnam War arose from the indecisive aftermath of political relations, the Third Indochina War again followed the unresolved problems of the earlier wars. The victors of
World War II, the United Kingdom, the United States, and the Soviet Union, all agreed that the area belonged to the French. As the French did not have the means to immediately retake Indochina, the major powers agreed that the British would take control and troops would occupy the south while
Nationalist Chinese forces would move in from the north. The British landed in the south and rearmed the small body of interned French forces as well as parts of the surrendered Japanese forces to aid in retaking southern Vietnam, as there were not enough British troops available. In January 1946, the
Viet Minh won elections across central and northern Vietnam. On 6 March 1946, Ho signed an agreement allowing French forces to replace Nationalist Chinese forces, in exchange for French recognition of the '
Democratic Republic of Vietnam' as a "free" republic within the
French Union, with the specifics of such recognition to be negotiated later. British forces departed on 26 March 1946, leaving Vietnam in the control of the French. The French landed in Hanoi by March 1946 and in November of that year they ousted the Viet Minh from the city. Rebellions against French colonial power were common up to
World War I. The European war heightened revolutionary sentiment in Southeast Asia, and the independence-minded population rallied around revolutionaries such as
Hồ Chí Minh and others, including royalists. Prior to their
attack on Pearl Harbor, the Japanese occupied
French Indochina, but left civil administration to the
Vichy French administration. The events leading to the First Indochina War have been subject to historical dispute. When the
Việt Minh hastily sought to establish the '
Democratic Republic of Vietnam', the remaining French acquiesced while waiting for the return of French forces to the region. The Soviets nonetheless remained less supportive than China until after the
Sino-Soviet split, during the time of
Leonid Brezhnev, when the Soviet Union became communist Vietnam's key ally. The war itself involved numerous events that had major impacts throughout Indochina. Two major conferences were held to bring about a resolution. Finally, on 20 July 1954, the
Geneva Conference resulted in a political settlement to reunite the country, signed with support from China, the Soviet Union, and Western European powers., it again was not as involved as China (dominated by
Mao Zedong). After the death of
Joseph Stalin in March 1953, relations between the Soviet Union and China began to deteriorate.
Mao Zedong believed the new Soviet leader
Khrushchev had made a serious error in
his Secret Speech denouncing Stalin in February 1956, and criticized the Soviet Union's interpretation of
Marxism–Leninism, in particular Khrushchev's support for
peaceful coexistence and its interpretation. This led to increasingly hostile relations, and eventually the
Sino-Soviet split. From here, Chinese communists played a decreasing role in helping their former allies because the Viet Minh did not support China against the Soviets. Following worsening
relations between the Soviet Union and China as a result of the
Sino-Soviet split of 1956–1966, as many as 1.5 million Chinese troops were stationed along the Sino-Soviet border in preparation for a full-scale war against the Soviets. Vietnam joined the
Council for Mutual Economic Assistance (CMEA) on June 28, 1978. Soviet military aid to Vietnam increased from $75-$125 million in 1977 to $600-$800 million in 1978. played an ever-increasing role in supporting South Vietnam through the period. The U.S. had supported French forces in the First Indochina War, sent supplies and military advisers to South Vietnam throughout the 1950s and early 1960s, and eventually took over most of the fighting against both North Vietnam and the
Viet Cong by the mid-1960s. By 1968, over 500,000 American troops were involved in the Vietnam War. On 20 January 1969,
Richard Nixon became US President. Due to a lack of clear military success and facing
increasingly strident opposition to the war in the U.S., American forces began a slow withdrawal in 1969 while attempting to
bolster South Vietnam's military so that they could take over the fighting. In accordance with the
Paris Peace Accords by 29 March 1973 all U.S. combat forces had left South Vietnam, however North Vietnamese combat forces were allowed to remain in place. North Vietnam
attacked South Vietnam in early 1975 and
South Vietnam fell on 30 April 1975. The PR China started talks with the United States in the early 1970s, culminating in high level meetings with
Henry Kissinger and later
Richard Nixon. These meetings contributed to a
re-orientation of Chinese foreign policy toward the United States. After Nixon's resignation on August 9, 1974,
Gerald Ford became US President.
Cambodia Although the Vietnamese Communists and the Khmer Rouge had previously cooperated, the relationship deteriorated when Khmer Rouge leader
Pol Pot came to power and established
Democratic Kampuchea on 17 April 1975. The
PR China, on the other hand, also supported the
Maoist Khmer Rouge against
Lon Nol's regime during the
Cambodian Civil War and its subsequent take-over of Cambodia. China provided extensive political, logistical and military support for the Khmer Rouge during its rule. After
numerous clashes along the border between Vietnam and Cambodia, and with encouragement from Khmer Rouge defectors fleeing purges of the Eastern Zone, Vietnam invaded Cambodia on 25 December 1978. By 7 January 1979, Vietnamese forces had entered Phnom Penh and the Khmer Rouge leadership had fled to western Cambodia. The offensive took the Chinese by surprise, and its Phnom Penh embassy fled to the jungle with the Khmer Rouge where it remained for 15 days.
Ethnic minorities China supported the ethnic minority
United Front for the Liberation of Oppressed Races against Vietnam during the
FULRO insurgency against Vietnam. The Vietnamese executed collaborators who worked for the Chinese, regardless of ethnicity. The Chinese received a significant number of defectors from the
Thu Lao ethnic minority in Vietnam during the war. During the war China received as migrants the entire A Lù based population of the
Phù Lá ethnic minority. China received so many defectors from the ethnic minorities in Vietnam that it raised shock among Vietnam which had to launch a new effort to re-assert dominance over the ethnic minorities and classify them. Post Vietnam War, an
insurgency against Vietnam lasted among the indigenous Mon-Khmer and Malayo-Polynesians of the Central Highlands. Assistance was sought from China by the
Hmong ethnic minority. The border was frequently crossed by Chinese, Lao, Kinh, Hmong, Yao, Nung, and Tai. The
Laotian Hmong and
FULRO were both supported against Vietnam by China and Thailand. In February 1976, Vietnam implemented registration programs in the south. (However, the Soviet Union had shifted from open animosity towards more normalized relations with China soon after.) Vietnam called for a special relationship between the three Indochinese countries, but the Khmer Rouge regime of Democratic Kampuchea rejected the idea. Beginning in fall 1978 and continuing through early 1979,
Deng Xiaoping made a series of international trips, one goal of which was to gauge world opinion on the issues between China and Vietnam. Deng sought an endorsement from the United States in order to deter the Soviet Union from intervening when China launched a punitive attack against Vietnam. According to academic
Suisheng Zhao, "[t]he proximity in the timing of the military thrust against Vietnam, was to take advantage of the normalization to bluff the Soviets with a nonexistent US endorsement." In addition, the bulk of China's active forces (as many as one-and-a-half million troops) were stationed along China's border with the Soviet Union. The 17 February issue of ''
People's Daily'' accuses Vietnam of discrimination against ethnic Chinese populations, of preparing to invade China, and of shooting at civilians and their properties from across the border on its front page. Another article, also on the front page, claims that the Foreign Ministry sent a diplomatic note expressing "the strongest protest" for Vietnamese incursions on Chinese soil. ==Course of war==