The Cambodian–Vietnamese War was an armed conflict from 1978 to 1989 between Democratic Kampuchea and the Socialist Republic of Vietnam, and their respective allies. It began in December 1978, with a Vietnamese invasion of Cambodia which toppled the Khmer Rouge regime and ended in 1989 with the withdrawal of Vietnamese forces from Cambodia. This Cold War conflict was part of the Third Indochina War and Sino-Soviet split with the Soviet Union supporting Vietnam and China supporting Kampuchea.
Despite both being communist, the alliance between the Communist Party of Vietnam and the Khmer Rouge broke down after both defeated Vietnamese and Cambodian anti-communist regimes respectively in the Second Indochina War. As a result, the war was preceded by years of conflict between Vietnam and the Khmer Rouge, led by Pol Pot, when the Khmer Rouge-ruled Democratic Kampuchea repeatedly invaded Vietnam, including massacres by the Khmer Rouge, notably the Ba Chúc massacre of over 3,000 Vietnamese civilians in April 1978. On 21 December 1978, the Vietnamese launched a limited offensive towards the town of Kratie. On 23 December 1978, 10 out of 19 divisions of the Khmer Rouge's Kampuchea Revolutionary Army opened fire along the border with Vietnam with the goal of invading the southwestern border provinces of Đồng Tháp, An Giang and Kiên Giang. On 25 December 1978, Vietnam supported Cambodian dissidents in exile and launched a full-scale invasion of Kampuchea, occupying the country in two weeks, capturing the capital Phnom Penh, and removing the Khmer Rouge government of the Communist Party of Kampuchea from power. In doing so, Vietnam put an ultimate stop to the Cambodian genocide which had killed between 1.2 and 2.8 million people or between 13 and 30 percent of the country's population since 1975. However, the Khmer Rouge regime maintained its membership in the United Nations and the war isolated Vietnam from the international community except the Eastern Bloc. The Vietnamese occupation caused discontent among Cambodians.
After the Cambodian capital was captured by the Vietnamese, another communist state was established to replace the old regime while the Khmer Rouge was forced to retreat into the jungle near the border with Thailand where the Khmer Rouge alongside the Khmer People's National Liberation Front, led by Son Sann, and FUNCINPEC, led by former king Norodom Sihanouk, continued to fight the Vietnamese army and the pro-Vietnamese Cambodian government. In 1982, they formed the Coalition Government of Democratic Kampuchea. Vietnam's goal of defeating the Khmer Rouge remnants could not be achieved while domestic difficulties forced Vietnam to gradually withdraw its troops. The Vietnamese army completely withdrew in September 1989, and in 1991 the Paris Peace Agreements were signed to open the process of reconciliation between Cambodia's factions, leading to a UN-led transition and the restoration of multi-party rule and a constitutional monarchy in the Kingdom of Cambodia in September 1993.
History
Vietnam War
"Khmer Rouge" is the name that was popularly given to members of the Communist Party of Kampuchea (CPK) established by separating from the Vietnamese dominated-Indochinese Communist Party (predecessor of the Communist Party of Vietnam). In 1951, Cambodian and Vietnamese communists fought France and its respective associated states, with the Cambodian communists leading the Khmer Issarak and the Vietnamese communists leading the Viet Minh. However, despite both winning and Vietnamese communists gaining North Vietnam north of the 17th parallel, with the Geneva Accords in July 1954, both failed to take control of their respective countries and Cambodian communists were not even allowed to take power anywhere by an agreement that the Vietnamese communists signed on their behalf, which led to the Vietnam War, including the Cambodian Civil War. In the context of the global Cold War, during the Vietnam War, Vietnamese and Cambodian communists again had formed an alliance to fight anti-communist regimes in their respective countries: the Republic of Vietnam (South Vietnam) and the Khmer Republic. Since its founding until 1975, the Khmer Rouge officially maintained good relations with the Communist Party of Vietnam. However, the Khmer Rouge led by Pol Pot also feared that the Vietnamese communists were planning to form an Indochinese federation, which would be dominated by Vietnam. Hanoi support for the Khmer Rouge diminished in 1973. The Khmer Rouge were also harboring irredentist sentiments about the Mekong Delta region. Both eventually took power over their respective countries in April 1975 with Vietnam being officially unified the following year. To pre-empt any attempt by the Vietnamese to dominate them, the Khmer Rouge leadership began, as the Lon Nol government capitulated in 1975, to purge Vietnamese-trained personnel within their own ranks. Then, in May 1975, the Khmer Rouge regime (later known as Democratic Kampuchea) began attacking southern Vietnam, beginning with an attack on the island of Phú Quốc (known as Koh Tral to the Cambodians).
Infighting
In spite of the fighting, the leaders of reunified Vietnam and Democratic Kampuchea made several public diplomatic exchanges throughout 1976 to highlight the supposedly strong relations between them. However, behind the scenes, Kampuchean leaders continued to fear what they perceived as Vietnamese expansionism. Therefore, on 30 April 1977, they launched another major military attack on Vietnam. Shocked by the Kampuchean assault, Vietnam launched a retaliatory strike at the end of 1977 in an attempt to force the Kampuchean government to negotiate. The Vietnamese military withdrew in January 1978, even though its political objectives had not been achieved; the Khmer Rouge remained unwilling to negotiate seriously.
Small-scale fighting continued between the two countries throughout 1978, as China tried to mediate peace talks between the two sides. However, the two governments could not reach a compromise. By the end of 1978, Vietnamese leaders decided to remove the Khmer Rouge-dominated government of Democratic Kampuchea, perceiving it as being pro-Chinese and hostile towards Vietnam. On 25 December 1978, 150,000 Vietnamese troops invaded Democratic Kampuchea and overran the Kampuchean Revolutionary Army in just two weeks, thereby ending Pol Pot's government, which had been responsible for the deaths of almost a quarter of all Cambodians between 1975 and December 1978 during the Cambodian genocide. Vietnamese military intervention, and the occupying forces' subsequent facilitation of international food aid to mitigate the massive famine, ended the genocide.
Establishment of the PRK
On 8 January 1979 the pro-Vietnamese People's Republic of Kampuchea (PRK) was established in Phnom Penh, marking the beginning of a ten-year Vietnamese occupation. During that period, the Khmer Rouge's Democratic Kampuchea continued to be recognised by the United Nations as the legitimate government of Kampuchea, as several armed resistance groups were formed to fight the Vietnamese occupation. Throughout the conflict, these groups received training in Thailand from the British Army's Special Air Service. Behind the scenes, Prime Minister Hun Sen of the PRK government approached factions of the Coalition Government of Democratic Kampuchea (CGDK) to begin peace talks. Under diplomatic and economic pressure from the international community, the Vietnamese government implemented a series of economic and foreign policy reforms, and withdrew from Kampuchea in September 1989.
At the Third Jakarta Informal Meeting in 1990, under the Australian-sponsored Cambodian Peace Plan, representatives of the CGDK and the PRK agreed to a power-sharing arrangement by forming a unity government known as the Supreme National Council (SNC). The SNC's role was to represent Cambodian sovereignty on the international stage, while the United Nations Transitional Authority in Cambodia (UNTAC) was tasked with supervising the country's domestic policies until a Cambodian government was elected by the people. Cambodia's pathway to peace proved to be difficult, as Khmer Rouge leaders decided not to participate in the general elections, but instead chose to disrupt the electoral process by launching military attacks on UN peacekeepers and killing ethnic Vietnamese migrants. In May 1993, Sihanouk's FUNCINPEC movement defeated the Cambodian People's Party (CPP), formerly the Kampuchean People's Revolutionary Party (KPRP), to win the general elections. However, the CPP leadership refused to accept defeat, and announced that the eastern provinces of Cambodia, where most of the CPP's votes were drawn from, would secede from Cambodia. To avoid such an outcome, Norodom Ranariddh, the leader of FUNCINPEC, agreed to form a coalition government with the CPP. Shortly afterward, the constitutional monarchy was restored and the Khmer Rouge was outlawed by the newly formed Cambodian government.
Cambodian–Vietnamese history
Angkor, the seat of the Khmer Empire, was subjected to Vietnamese influence as early as the 13th century. Vietnamese influence spread gradually and indirectly, and it was not until the early 19th century that Vietnam exercised direct control. However, Vietnamese attempts to annex Cambodia began in the 17th century when Vietnamese forces of the Nguyen domain in Cochinchina helped Cambodian dissidents topple its only Muslim king, Ramathipadi I. From then on, Nguyen lords and their successors, Nguyen emperors frequently intervened in Cambodia. In 1813, Nak Ong Chan gained the Cambodian throne with the help of Vietnam, and under his rule Cambodia became a protectorate. Following his death in 1834, the Vietnamese empire under Minh Mang, who held strong Confucian beliefs, annexed and colonised Cambodia. Cambodia was governed under a Vietnamese administration in Phnom Penh and termed a Vietnamese province. The Vietnamese emperor attempted to erase Khmer culture, which had derived the basis of Cambodian society, dress, and religion from India rather than China. The trend of Vietnamese dominance continued during French colonisation, under which the former southern region of Cambodia (the Saigon region, the Mekong Delta and Tây Ninh) was integrated into the French colony Cochinchina. The Khmer Rouge later justified their incursions into Vietnam as an attempt to regain the territories which Cambodia had lost during the previous centuries.
Rise of communism
The communist movement in Cambodia and Vietnam began before World War II with the founding of the Indochinese Communist Party (ICP), almost exclusively dominated by the Vietnamese, originally meant to fight French colonial rule in Indochina. In 1941, Nguyen Ai Quoc (commonly known by his alias Ho Chi Minh) founded the Viet Nam Doc Lap Dong Minh Hoi, or the Viet Minh. After the Japanese army claimed to surrender to the Allies in World War II, his force overthrew the Vietnamese monarchy and later initiated the First Indochina War against the French. During this time, Vietnamese forces made extensive use of Cambodian territory to transport weapons, supplies, and troops. This relationship lasted throughout the Vietnam War, when Vietnamese communists used Cambodia as a transport route and staging area for attacks on South Vietnam.
In 1951, Vietnamese communists guided the establishment of a separate Cambodian communist party, the Kampuchean People's Revolutionary Party (KPRP), which allied with a nationalist separatist Cambodian movement, the Khmer Serei (Free Khmers), to pursue independence. In accordance with the 1954 Geneva Accords on Indochina negotiating the end of the war between communist resistance forces and the French Union, newly created communist North Vietnam pulled all of its Viet Minh soldiers and cadres out of Cambodia. Since the KPRP was staffed primarily by ethnic Vietnamese or Cambodians under its tutelage, approximately 5,000 communist cadres went with them.
The power vacuum the Vietnamese communists left in their wake in Cambodia was soon filled by the return of a young group of Cambodian communist revolutionaries, many of whom received their education in France. In 1960, the KPRP changed its name to the Kampuchean Communist Party (KCP), and the name was later adopted by the majority coalition that formed around Saloth Sar (Pol Pot), Ieng Sary, and Khieu Samphan as the successor to the KCP. This clique became the genesis of the Khmer Rouge, and its doctrine was heavily influenced by Maoist ideology.
Lon Nol's anti-Vietnamese sentiment
After the removal of Sihanouk from power in March 1970, the leader of the new Khmer Republic, Lon Nol, despite being anti-communist and ostensibly in the "pro-American" camp, backed the FULRO against both anti-communist South Vietnam and the communist Viet Cong. Following the 1970 coup, thousands of Vietnamese Cambodians were massacred by forces of Lon Nol. Many of the dead were dumped in the Mekong River. 310,000 ethnic Vietnamese fled Cambodia as a result. The Khmer Rouge would later murder the remaining Vietnamese in the country during their rule.
Ideology of the Khmer Rouge
The Khmer Rouge government adopted the mysterious term Angkar, or 'the organisation', and the identities of its leaders remained confidential until 1977. The official head of state was Khieu Samphan, but the two men in control of the party were Pol Pot and Ieng Sary. The ultimate objective of the Khmer Rouge was to erase the structure of the Cambodian state, which they viewed as feudal, capitalist, and serving the agendas of both the landholding elite and imperialists. In its place, they hoped to create a classless society based entirely on worker-peasants. The radical ideologies and goals of the Khmer Rouge were alien concepts to the masses. The socialist revolution held very little popular appeal, which led Pol Pot and his cadres to use ultra-nationalist sentiment, repressive and murderous rule, and propaganda aimed at demonising the Vietnamese to maintain control.
A major point of departure between the Khmer Rouge faction and the Vietnam-aligned Communist Party of Kampuchea, which has favored more classical Marxism–Leninist ideology, was the Khmer Rouge's embrace of a nationalistic form of Maoism, one of the few major communist parties to do so in the wake of the Sino-Soviet split. This served as the basis for the Khmer Rouge's agrarian policies.
Even before the Vietnam War ended, the relationship between the Khmer Rouge—which was in the process of seizing power from a US-backed government headed by Lon Nol—and North Vietnam was strained. Clashes between Vietnamese communists and Khmer Rouge forces began as early as 1974, and the following year Pol Pot signed a treaty codifying the "friendship" between the Khmer Rouge and China.