Vietnamese Troops Withdraw from Cambodia

Following ten years of embattled occupation, Vietnamese military forces withdrew from Cambodia in 1989, allowing political and military conflicts among Cambodia’s political factions to escalate.

Summary of Event

The Communists’ successful conclusion of the war for national unification in Vietnam in 1975 was accompanied by decisive military victories by local Communist organizations in both Laos and Cambodia. Although the leaderships that came to power in all of the three former states of French Indochina were Communist, they had different prescriptions for postwar development and social reorganization in their nations. These dissimilar views, combined with separate links to the rival Communist superpowers, the Soviet Union and the People’s Republic of China, brought the Communist parties of Cambodia and Vietnam into political and military conflict in the late 1970’s. Vietnam;occupation of Cambodia
Cambodia;Vietnamese occupation
[kw]Vietnamese Troops Withdraw from Cambodia (Sept., 1989)
[kw]Troops Withdraw from Cambodia, Vietnamese (Sept., 1989)
[kw]Withdraw from Cambodia, Vietnamese Troops (Sept., 1989)
[kw]Cambodia, Vietnamese Troops Withdraw from (Sept., 1989)
Vietnam;occupation of Cambodia
Cambodia;Vietnamese occupation
[g]Southeast Asia;Sept., 1989: Vietnamese Troops Withdraw from Cambodia[07380]
[g]Cambodia;Sept., 1989: Vietnamese Troops Withdraw from Cambodia[07380]
[c]Wars, uprisings, and civil unrest;Sept., 1989: Vietnamese Troops Withdraw from Cambodia[07380]
[c]Terrorism, atrocities, and war crimes;Sept., 1989: Vietnamese Troops Withdraw from Cambodia[07380]
[c]Colonialism and occupation;Sept., 1989: Vietnamese Troops Withdraw from Cambodia[07380]
Pol Pot
Hun Sen
Sihanouk, Norodom
Heng Samrin
Son Sann
Khieu Samphan

Clashes along the Vietnam-Cambodia border and the growing cooperation between China and Cambodian Communists, known as the Khmer Rouge, Khmer Rouge prompted the militarily superior, Soviet-backed Vietnamese to launch a rapid invasion of Cambodia in late December, 1978. This military operation led to the capture of the capital city of Phnom Penh, the displacement of the Khmer Rouge government ruling what was known as Democratic Kampuchea, and the installation of a pro-Vietnamese Communist government to run the renamed People’s Republic of Kampuchea.

The principal architect of Khmer Rouge policies was Saloth Sar, popularly known as Pol Pot. During the period of Khmer Rouge rule in Cambodia, from 1975 to early 1979, Pol Pot’s wing of the Cambodian Communist movement initiated a program of systematic political repression, the ostensible objective of which was to transform Cambodia rapidly into a self-sufficient Communist state in which all distinctions of class and social status would be eliminated.

To achieve this goal, the Khmer Rouge carried out forced population relocation campaigns on a mass scale and at one time contemplated the annihilation of all Cambodians over the age of twelve years so that no influences outside the control of the leadership would persist into the new era of self-sufficiency and revolutionary purity. Civil servants, teachers, professionals, and even those who were simply able to read were singled out by the Khmer Rouge for torture and interrogation. Many of those viewed as “most dangerous” were imprisoned, tortured until they “confessed” to political crimes, and then executed at Tuol Sleng, formerly Phnom Penh’s largest primary and secondary school. It has been estimated that at least one million Cambodians died from starvation and the repressive policies of the Khmer Rouge during the 1975-1979 period.

Although Vietnam claimed that its 1979 invasion of Cambodia was motivated by a desire to end the suffering of the Cambodian people, Vietnam’s own national security concerns were probably the most important factor in the decision to invade. Vietnamese leaders were concerned about Khmer Rouge contacts with the People’s Republic of China as well as about Khmer Rouge military incursions along Vietnam’s southwestern border with Cambodia. The Vietnamese invasion drove Khmer Rouge forces from this region and, soon thereafter, from the capital at Phnom Penh. The Khmer Rouge leadership and military command structure, however, survived the invasion largely intact. After establishing new positions along the border with Thailand, the Khmer Rouge continued its recruitment and political indoctrination activities throughout the decade of Vietnamese occupation while also receiving diplomatic and material assistance from both the People’s Republic of China and the United States.

The Vietnamese military occupation was legally authorized under the terms of the February 18, 1979, Treaty of Solidarity concluded between Vietnam and the newly installed pro-Vietnamese government of Cambodia led by Heng Samrin and Hun Sen, both of whom had been commanders in the Khmer Rouge until their defection to Vietnam in 1978. Official Vietnamese accounts credit Vietnamese “volunteers” (soldiers) with carrying out disaster relief, resettlement, and construction projects in Cambodia between 1979 and 1989. Much progress was made, especially in the redevelopment of some export goods sectors, but a population growth rate of 2.8 percent per year, inflation caused by price-restructuring initiatives, and the perennial guerrilla conflict with the Khmer Rouge inhibited Cambodia’s economic activity. For the 80 percent of the Cambodian people employed in agriculture, conditions continued to be harsh. A 1988 study conducted by the United Nations revealed that per-capita caloric intake in Cambodia dropped during the period of Vietnamese military occupation.

Vietnam’s decision to withdraw from Cambodia emerged from an evaluation of developments in the international arena. Political changes in the Soviet Union brought into question continuance of Soviet subsidies for Vietnam and seemed to portend a reduction in Sino-Soviet military tensions, a key factor in the conflict in Indochina. Following interparty contacts in late 1988 between Chinese and Vietnamese Communists and the arrangement of Soviet leader Mikhail Gorbachev’s visit to Beijing in the spring of 1989, Vietnam announced on April 5, 1989, that its preconditions for a full troop withdrawal from Cambodia had been abandoned. Vietnam declared that all of its forces would leave Cambodia by the end of September, 1989, even if no political settlement between the Hun Sen government and the Khmer Rouge could be reached by that time.

In response, a flurry of activity developed during the summer of 1989. A major international conference was convened in Paris during August, but the representatives who attended failed to reach agreement on the issue of Khmer Rouge participation in any new coalition government. The negotiations were greatly complicated by the demands of the two non-Communist political factions formally allied with the Khmer Rouge, the Khmer People’s National Liberation Front Khmer People’s National Liberation Front (KPNLF), led by Son Sann, and the forces led by former head of state Prince Norodom Sihanouk and his son, Prince Norodom Ranariddh.

Soon after the Paris conference disbanded, press reports indicated that the three allied factions were preparing for an escalation of the military conflict with the Phnom Penh government. The Khmer Rouge was believed to be receiving increased deliveries of Chinese weapons, while the United States and the non-Communist Association of Southeast Asian Nations Association of Southeast Asian Nations (ASEAN) reportedly developed covert military training and weapons supply programs aimed at strengthening the KPNLF and the Sihanoukists. Following a visit to Hanoi by a high-level delegation from Phnom Penh in early September, 1989, Vietnamese diplomats announced that the withdrawing forces would take “maximum precautions” to ameliorate the effects of an anticipated Khmer Rouge offensive against the Phnom Penh government’s forces.

Beginning in mid-September, as Vietnamese forces left western Cambodia, Khmer Rouge forces based in the area launched a major offensive. The Khmer Rouge strategy appeared to be to capture substantial areas of the country as a means of securing participation in a coalition government. To that end, Khmer Rouge troops forced thousands of refugees living in camps near the Thai border to relocate to recently captured territory further inside western Cambodia. This policy continued during 1990, affecting as many as 100,000 refugees. Similar relocation programs were reportedly initiated by troops of the two non-Communist political factions, which were also active in western Cambodia.

In early September, 1989, the pro-Vietnamese party leader Heng Samrin promised that to promote national harmony, his party and the Phnom Penh government would show leniency for those people who had previously supported any of the other Cambodian political groupings. Phnom Penh, however, employed harsh methods to maintain its own military organizations in the absence of Vietnamese forces. The pro-Vietnamese government authorized military recruitment campaigns that were based on compulsory draft regulations for both active military and auxiliary service. Among the recruitment tactics, reportedly, were surprise raids to round up urban youths, including students. It was said that Phnom Penh youths, fearful of being press-ganged into the military, were going into hiding. Officials attempted to broaden the appeal of military service by changing the army’s name from the Kampuchean People’s Revolutionary Armed Forces to the Cambodian People’s Armed Forces. Nevertheless, a steady stream of deserters, many between fifteen and nineteen years of age, sought refuge in Thailand.

For the Vietnamese forces withdrawn from Cambodia in 1989, the return to Vietnam involved difficult adjustments. Estimates (which may be conservative) put the number of Vietnamese soldiers killed during the occupation period at 23,500; another 55,000 reportedly were seriously wounded. Returning units were visited and congratulated by high-ranking Vietnamese officials, and public receptions emphasized the “victory” obtained in Cambodia. The urgency behind the withdrawal policy was suggested, however, by official reports of the demobilization of returning divisions within four days of their reaching Vietnam. The Vietnamese government promised veterans comprehensive benefits, but reports indicated that demobilized soldiers faced numerous economic difficulties, including shrinking public welfare budgets, housing shortages, and shifting employment patterns.


When the Vietnamese military finalized its formal withdrawal from Cambodia in late September, 1989, the official press in Vietnam marked the occasion with tributes to the troops’ successful completion of their “internationalist duty.” Official accounts cited the need to “respond to the Cambodian people’s urgent call for help” after nearly four years of Khmer Rouge rule as the chief reason for the 1979 invasion and referred to the need to “cope with the enemy’s counterrevolutionary attack” as the chief reason for the decade-long military occupation. Nevertheless, Vietnam’s withdrawal took place while the Khmer Rouge still maintained a stable organizational structure, a leadership that included such key figures from the 1975-1979 period as Pol Pot and Khieu Samphan, and a military wing of active soldiers estimated at some thirty thousand. The principal effect of Vietnam’s withdrawal from Cambodia was to stimulate a reescalation of the civil war between the Khmer Rouge, along with its non-Communist coalition partners, and the pro-Vietnamese Communist government.

The inability of the four main Cambodian political organizations to reach agreement on a political settlement in 1989 was therefore accompanied by growing military conflict, especially in the western portion of the country. In this area, the effects of the continuing conflict were immediately apparent: youths drafted into military service, refugee families forcibly relocated, and rice fields destroyed or abandoned.

In addition to new battles in western Cambodia, there remained the potential for tensions throughout the country between Cambodians and the one million ethnic Vietnamese who settled in Cambodia during the occupation period under Vietnamese government relocation programs. In official documents circulated at the United Nations, the Khmer Rouge described these settlers as being organized into multifamily units from which were drawn around sixty thousand paramilitary forces and fifty thousand administrative and intelligence cadres. The documents predicted clashes between these Vietnamese living in Cambodia and the Cambodians themselves and charged that since 1987 the Vietnamese occupiers had constructed an elaborate system of arms caches inside Cambodian territory, the purpose of which was to supply these informal Vietnamese forces after the September, 1989, withdrawal.

The chronic nature of the devastation in northwestern Cambodia, where most of the fighting occurred, was evident in press reports in the spring of 1991 indicating that in the region the mortality rate for children under five years of age was around 20 percent, civilian injuries caused by land mines Land mines led to three hundred amputations per month, and around 10 percent of the region’s population had been displaced by war. The number of refugees in U.N. camps near the Thai border was estimated at 330,000, up from 250,000 in early 1990. According to observers, an unprecedented degree of despair and resignation prevailed among ordinary Cambodians, who were unable to conceive of a future without continued military conflict, political repression, and physical suffering.

Despite the immediate negative consequences, the Vietnamese withdrawal also in the long run paved the way for peace talks prompted and supported by China, France, Russia, the United Kingdom, and the United States. These talks produced an agreement in 1991 that led to the deployment of the U.N. Transitional Authority in Cambodia United Nations Transitional Authority in Cambodia (UNTAC), which oversaw repatriation and relocation of refugees and displaced persons, provision of humanitarian and development aid, a demobilization of forces, clearance of land mines, and democratic elections, in which Khmer Rouge forces were popularly repudiated. Although not without setbacks, the UNTAC operation put the country back on the road to political stability and greater economic and social well-being. Vietnam;occupation of Cambodia
Cambodia;Vietnamese occupation

Further Reading

  • Becker, Elizabeth. When the War Was Over: Cambodia and the Khmer Rouge Revolution. 1986. Reprint. New York: PublicAffairs, 1998. Well-written account of the Khmer Rouge period in Cambodia includes attention to the cultural context and to the individual victims and Khmer Rouge officials. The author’s experiences in Cambodia in the days before Vietnam’s invasion add interest, and her use of archival material from the Khmer Rouge torture complex at Tuol Sleng is especially noteworthy.
  • Coates, Karen J. Cambodia Now: Life in the Wake of War. Jefferson, N.C.: McFarland, 2005. Describes life in Cambodia after decades of war. Includes photographs, map, glossary, time line, bibliography, and index.
  • Duiker, William J. Vietnam Since the Fall of Saigon. Athens: Ohio University Center for International Studies, 1989. Provides an informative account of Hanoi’s domestic and foreign policies after 1975. Chapters 6 and 9 deal with Vietnam’s invasion and occupation of Cambodia and the importance of the Chinese dimension of these policies.
  • Evans, Grant, and Kevin Rowley. Red Brotherhood at War: Vietnam, Cambodia, and Laos Since 1975. London: Verso, 1990. Presents a detailed picture of relations between Communist organizations in Indochina after 1975, emphasizing the nationalist roots of conflicts and rivalries. Covers diplomatic and battlefield developments through the middle of 1989, when Vietnam’s formal withdrawal of troops from Cambodia was announced.
  • Hiebert, Murray. “Standing Alone.” Far Eastern Economic Review 43 (June 29, 1989): 17-18. Offers a succinct description of the internal military situation in Cambodia as Vietnamese troops prepared for withdrawal. The same issue of this journal contains other articles by Hiebert examining political and economic aspects of Vietnam’s changing policies toward Cambodia.
  • Kiernan, Ben. How Pol Pot Came to Power: Colonialism, Nationalism, and Communism in Cambodia, 1930-1975. 2d ed. New Haven, Conn.: Yale University Press, 2004. Presents one of the most detailed pictures available in English of the origins of the Cambodian Communist movement and its long-standing links to the Vietnamese Communist organization. Provides essential background for understanding the dynamics of Vietnam’s relations with both the Khmer Rouge and the government of Heng Samrin and Hun Sen.

Khmer Rouge Comes to Power in Cambodia

China Invades Vietnam

Hun Sen Wins Cambodian Elections