The Two-Faced Enemy in Cambodia 1979-1985

 The Two-Faced Enemy in Cambodia 

1979-1985

Against the backdrop of Vietnam’s socioeconomic crisis precipitated by the failed planned socialist economy in the post-1975 unification and the embargo imposed by the United States after 1975, the Vietnamese invasion and occupation of Cambodia from December 1978 to 1989 contributed significantly to Vietnam’s economic stagnation and caused military conflict with China and political confrontation with ASEAN, further isolating Vietnam in the region during this period. To political elites in Vietnam today, the invasion of Cambodia in December 1978 was a justified response to Khmer Rouge provocations but the occupation of Cambodia for the next decade was a costly mistake.¹ In addition to economic stagnation in Vietnam, the cost of the occupation was estimated at US$2 million a day throughout most of the 1980s, mostly covered by Soviet aid to Vietnam. Vietnamese casualties were estimated at 117,000 between 1977 and 1989.² Today in Vietnam’s official history the Vietnamese army “gloriously fulfilled its duty to help the Cambodian people wholeheartedly and unselfishly.”³ If so, why is Vietnam’s military presence in Cambodia during this period deeply contested in Cambodia? This chapter provides a narrative of seldom discussed events during Vietnam’s military intervention in Cambodia in 1979–83.

Today in Vietnam, behind the official history of its noble mission in Cam- bodia, there is a debate over why Vietnam stayed on to occupy Cambodia for another decade after the invasion. The common explanation is that the PRK,

the regime that Hanoi installed after 1979, would not have survived without the Vietnamese military opposing Cambodian resistance forces, a joint anti-Vietnamese alliance represented by the Coalition of Government of Democratic

Kampuchea (CGDK), established in June 1982. The anti-Vietnamese and PRK alliance among the royalist faction (with Sihanouk as its leader) republicans (led by Son Sann), and communists (led by Khieu Samphan) was backed by China, the United States, and ASEAN, and, with the support of those nations, it retained the Cambodian United Nations seat after October 1979.⁵ The PRK under its first president, Heng Samrin, along with Vietnam itself, was isolated and politically delegitimized by the West as Hanoi's puppet regime.

The historical representation of Vietnam’s invasion and occupation—liberation and nation building—of Cambodia during the decade from 1978 to 1988 is controversial and deeply contested in public political discourses in Cambodia. This emotionally and politically charged issue divides the Cambodian people and rallies factions behind two radically different historical representations of the event by the two major political parties in Cambodia: the CPP, the ruling party; and the CNRP, the opposition. While branding itself as democratic, the CNRP has articulated and perpetuated an anti-Vietnamese nationalist discourse and exploited the CPP’s political debt to its Vietnamese patrons in Hanoi in the late 1970s and 1980s. On the other hand, the ruling CPP has always emphasized Vietnam’s assistance in the liberation of the Cambodian people from the Pol Pot genocidal regime, a legacy that the CPP inherited and incorporated into its political identity of terminating the Khmer Rouge political and military movement and bringing total peace to Cambodia. The CPP has accused the CNRP leadership of stirring up anti-Vietnamese racism in Cambodia and fomenting Cambodian-Vietnamese antagonism for its own party’s political gain.

This chapter provides insight into the murky period of Vietnam’s occupation of Cambodia (1979–83) during which, we now know, the CPV attempted to export the Vietnamese revolution and socialist model to Cambodia after overthrowing the DK, better known as the Khmer Rouge regime, in January 1979. Documents, memoirs, and interviews reveal the human and material cost of Vietnam’s bloody war in Cambodia and Vietnam’s occupation. The bulk of the evidence presented below shows that the moral urgency with which the Hanoi leadership carried out its mission of nation building in Cambodia after overthrowing the Pol Pot regime in 1979 was soon challenged by the reality of Cambodia’s growing insurgency and resistance against the Vietnamese occupying forces.

The Vietnamese Volunteer Army (VVA), dubbed “Buddha’s army” by Cambodian prime minister Hun Sen,  was given a mission under the slogan “Helping our [Cambodian] friends is helping ourselves.” To be sure, the Vietnamese volunteers were regular soldiers. Cambodian popular perception of the Vietnamese troops changed from seeing them as “liberators” to seeing them as “occupiers”

In just a few years, the CPV’s self-proclaimed moral high ground in liberating Cambodia from the Pol Pot regime and making considerable sacrifices for the new Cambodian revolution it established gave leaders of the Vietnamese occupying forces the moral self-license to take extraordinary measures, including the arrest and torture of many Cambodian officials suspected of serving as a fifth column for Cambodian resistance forces against the Vietnamese. Moral self-license is a phenomenon whereby behaviors that initially establish people’s morality can subsequently disinhibit them and allow them to behave in ways that are immoral or frivolous.¹⁰ Moral self-license, a concept I borrow from social psychology,¹¹ best captures the behaviors and attitudes of some Vietnamese generals and political leaders who oversaw Cambodian affairs that occurred as part of Vietnam’s “noble mission” in Cambodia. These actions rapidly eroded Vietnam’s moral capital and inspired resistance, defection, and mistrust among the general populace and Cambodian authorities, causing major damage to Vietnam’s nation-building mission.

Vietnam’s determination to prevent a humanitarian crisis, including mass starvation, after the collapse of the Pol Pot regime in early 1979 was admired by the Cambodian people. But as Vietnam’s nation-building mission shifted from an emphasis on restoring livelihoods and economic productivity while building a socialist system between 1979 and 1980 to achieving military victory on the battlefield from 1981 to 1983, the Vietnamese military saw the need to purge “two-faced authorities” (chinh quyen hai mat) and “hidden enemies” (dich ngam) within Cambodian society. The impact of the Vietnamese purges gravely soured the relationship between the Vietnamese army and the Cambodian people, rapidly eroding Vietnam’s goodwill and moral capital just a few years after it liberated the Cambodian people from genocide in 1979.

Exporting the Vietnamese Revolution to Cambodia

In mid-1979, Military Region 7 of the PAVN was confronted with a tough guerrilla war against Cambodian resistance forces with between 22,000 and 25,000 combatants in the northeastern region of Cambodia.12 This vast region includes the two northern provinces of Battambang and Siem Reap and the four central and northeastern provinces of Kampong Thom, Kampong Cham, Kratie, and Svay Rieng. But the majority of the Cambodian resistance forces, with nearly 20,000 combatants, operated in three important provinces: Battambang, Siem Reap, and Kampong Thom. In the first half of 1979, the forces of Military Region 7 concentrated on wiping out the enemy forces, protecting convoys, and retaining control over strategic territory along the main national roads, especially National Roads 5 and 6 connecting Phnom Penh and the provinces of Battambang and Siem Reap.

From February 12 to March 20, 1979, the Third Army of the PAVN was ordered to take charge of the battle in Siem Reap and Battambang so that Military Region 7 could dispatch its three main divisions—5, 302, and 303—to wipe out regrouped Khmer Rouge forces in Kampong Thom Province. The Military Region 7 commander claimed a major victory; according to the Vietnamese Ministry of National Defense, Vietnamese troops killed 546 enemy combatants and took 1,221 prisoners while 11,124 enemy combatants defected. The Vietnamese also liberated some 20,000 villagers from enemy control, confiscated 3,515 tons of rice and 20 tons of salt, and provided food to save these villagers from starvation.13 However, having won this military victory, the Vietnamese would find it much more difficult to retain control over the acquired territory.

At the urgent request of the Military Region 7 command, in April 1979 the Vietnamese MoD dispatched the newly established Division 317, consisting of six regiments (five infantry regiments—775, 747, 115, 770, and 329—and one artillery regiment, 774) to keep control of this strategically important central province of Cambodia.

With the approval of the Central Military Commission, Military Region 7 separated its main force of volunteer troops and military specialists into two fronts, Front 479 and Front 779. On April 14, 1979, the Front 479 command was established.15 On May 11, the MoD issued Decision 553/QD-QP to place Front 479 under the direct command of Military Region 7, and it was put in charge of the northern region of Cambodia, including the provinces of Battambang, Siem Reap, and Uddar Meanchey. General Bui Thanh Van, a native of the Vietnamese province of Tay Ninh on the border with Cambodia, was appointed commander of Front 479, and Major Le Thanh was named political commissar.16 Early on, the organizational structure of Front 479 included the central command, three departments (general staff, political, and logistics), four divisions (5, 302, 309, and 317), six infantry regiments (6, 7, 160, 205, 726, and 740), and five army regiments.17 Mimicking the military regions in Vietnam, the central command of the VVA in Cambodia was established to directly command the newly created fronts. Front 479 assumed major responsibility, including raids to wipe out enemy forces, liberate people from the enemy's control, help build the Cambodian revolutionary armed forces, and consolidate the Cambodian revolutionary government under its jurisdiction.

Before overthrowing the Pol Pot regime, Hanoi devised a two-stage plan to stabilize the Cambodian people's livelihoods and restore economic productivity. The first phase, from December 1978 to January 1979, entailed rapid

distribution of supplies to meet basic needs, including food and medicine. In the second phase, Hanoi planned to continue its assistance until aid from the Soviet Union and other socialist states arrived.19 By the end of January 1979, the Vietnamese government had transported a total of 3,771.7 tons of emergency supplies to Cambodia, including 250 tons of salt, 5.5 tons of sugar, 16.2 tons of fuel, 3,500 tons of grain, and medicine of all kinds to prevent mass starvation. This saved many Cambodian lives after the genocide. Vietnam also sent a number of other basic household goods, including cloth (530,000 meters), plates, bowls, knives, and spoons. Hanoi also ordered eight southern provinces of Vietnam to send similar temporary material aid to Cambodia. These deliveries accounted for less than 50 percent of the planned supplies; Hanoi planned to send the rest by June 1979.20 The main reason for the delay was simply that Vietnam was also a poor country that had just survived its own twenty-year war.

To support the new regime in Cambodia, Hanoi looked to the Soviet Union to provide what it could not, especially grain, cloth, medicine, communications equipment, means of transportation, vehicles, fuels, steel, cement, construction materials, and other raw materials for manufacturing.21 Nevertheless, Vietnam's emergency aid prevented mass starvation in the first few weeks after the end of the Pol Pot regime.

National Roads 5 and 6 connecting Phnom Penh and the provinces of Battambang and Siem Reap.

From February 12 to March 20, 1979, the Third Army of the PAVN was ordered to take charge of the battle in Siem Reap and Battambang so that Military Region 7 could dispatch its three main divisions—5, 302, and 303—to wipe out regrouped Khmer Rouge forces in Kampong Thom Province. The Military Region 7 commander claimed a major victory; according to the Vietnamese Ministry of National Defense, Vietnamese troops killed 546 enemy combatants and took 1,221 prisoners while 11,124 enemy combatants defected. The Vietnamese also liberated some 20,000 villagers from enemy control, confiscated 3,515 tons of rice and 20 tons of salt, and provided food to save these villagers from starvation.13 However, having won this military victory, the Vietnamese would find it much more difficult to retain control over the acquired territory.

At the urgent request of the Military Region 7 command, in April 1979 the Vietnamese MoD dispatched the newly established Division 317, consisting of six regiments (five infantry regiments—775, 747, 115, 770, and 329—and one artillery regiment, 774) to keep control of this strategically important central province of Cambodia.

With the approval of the Central Military Commission, Military Region 7 separated its main force of volunteer troops and military specialists into two fronts, Front 479 and Front 779. On April 14, 1979, the Front 479 command was established.15 On May 11, the MoD issued Decision 553/QD-QP to place Front 479 under the direct command of Military Region 7, and it was put in charge of the northern region of Cambodia, including the provinces of Battambang, Siem Reap, and Uddar Meanchey. General Bui Thanh Van, a native of the Vietnamese province of Tay Ninh on the border with Cambodia, was appointed commander of Front 479, and Major Le Thanh was named political commissar.16 Early on, the organizational structure of Front 479 included the central command, three departments (general staff, political, and logistics), four divisions (5, 302, 309, and 317), six infantry regiments (6, 7, 160, 205, 726, and 740), and five army regiments.17 Mimicking the military regions in Vietnam, the central command of the VVA in Cambodia was established to directly command the newly created fronts. Front 479 assumed major responsibility, including raids to wipe out enemy forces, liberate people from the enemy's control, help build the Cambodian revolutionary armed forces, and consolidate the Cambodian revolutionary government under its jurisdiction.

Before overthrowing the Pol Pot regime, Hanoi devised a two-stage plan to stabilize the Cambodian people's livelihoods and restore economic productivity. The first phase, from December 1978 to January 1979, entailed rapid

distribution of supplies to meet basic needs, including food and medicine. In the second phase, Hanoi planned to continue its assistance until aid from the Soviet Union and other socialist states arrived.19 By the end of January 1979, the Vietnamese government had transported a total of 3,771.7 tons of emergency supplies to Cambodia, including 250 tons of salt, 5.5 tons of sugar, 16.2 tons of fuel, 3,500 tons of grain, and medicine of all kinds to prevent mass starvation. This saved many Cambodian lives after the genocide. Vietnam also sent a number of other basic household goods, including cloth (530,000 meters), plates, bowls, knives, and spoons. Hanoi also ordered eight southern provinces of Vietnam to send similar temporary material aid to Cambodia. These deliveries accounted for less than 50 percent of the planned supplies; Hanoi planned to send the rest by June 1979.20 The main reason for the delay was simply that Vietnam was also a poor country that had just survived its own twenty-year war.

To support the new regime in Cambodia, Hanoi looked to the Soviet Union to provide what it could not, especially grain, cloth, medicine, communications equipment, means of transportation, vehicles, fuels, steel, cement, construction materials, and other raw materials for manufacturing.21 Nevertheless, Vietnam's emergency aid prevented mass starvation in the first few weeks after the end of the Pol Pot regime.

From October 18 to November 24, 1979, a powerful conservative leader, Le Duc Tho, chief of Vietnam's nation-building mission, and General Le Duc Anh, commander of the VVA in Cambodia, convened a general conference on the tasks to be undertaken by specialists in Cambodia. By October 1979, 1,284 Vietnamese specialists were already working in Cambodia, 300 specialists served the central government of Cambodia, and 1,300 more had been dispatched to assist the provinces. Vietnamese specialists in the provinces and districts were in charge of supervising economic and cultural specialists. Committee B68 and the on-site military commands were in charge of supervising economic and cultural specialists at the Party Central Committee in Phnom Penh.22 All leaders of the military specialists (group A40), economic-cultural specialists (K79), and public security (state police) specialists were instructed to attend the 1979 conference.

In a speech delivered at the conference, Le Duc Tho expressed his pleasure over Vietnam's historic achievement in building a revolutionary government and army in Cambodia during the previous twelve months. He reported that by the end of 1979 the Vietnamese had helped the PRK establish 46,000 production groups, known as "solidarity groups" (krom samaki in Khmer), in the liberated territory throughout Cambodia. Each group included a cluster of ten to fifteen families with twenty to thirty workers who were to cultivate some twenty hectares of land. Central to the establishment of these collective farming cooperatives was the idea that they would boost production efficiency, share any grain surplus with the state, and strengthen national defense. At the conference, Tho remarked, "These production groups not only restore economic productivity, but they also strengthen political stability and provide a security buffer at the local level."24 This idea was lifted directly from the Vietnamese Communists' socialist political economy manual, introduced in North Vietnam between 1958 and 1961. 

Tho reminded the Vietnamese specialists to uphold three principles when working with their Cambodian counterparts: (1) respect Cambodia's sovereignty, laws and regulations, and people; (2) refrain from big-country chauvinism; and (3) let the Cambodians make their own decisions. In other words, the Vietnamese were to assist their Cambodian comrades without patronizing them and encourage their self-reliance. The Vietnamese were to simply offer recommendations and leave final decisions to their Cambodian comrades. Tho remarked, "In the beginning, our friends [the Cambodians] lack knowledge. We have knowledge, and our Cambodian comrades learn [from us]. Then our Cambodian comrades start to join us in doing some work together. Next they carry out these tasks, and we simply observe or help when necessary. And finally, they can take over the work and do it independently, and we gradually withdraw." Central to Tho's instructions to the Vietnamese specialists and advisors was the importance of always being sensitive to the "political issue" of Cambodia's independence and sovereignty.

On December 20, 1979, on Le Duc Tho's recommendation, the People's Revolutionary Council of Cambodia decided to collect agricultural taxes and force peasants to sell all their farm yields to the state (at well below the market price). In addition, the state supplied rice seeds, fertilizer, and other agricultural necessities to the peasants and ensured the availability of irrigation.27 Tho and his associates were pleased that this policy speedily encouraged people to join "solidarity groups" and that Cambodian villagers were able to feed their families, which in turn reduced their dependence on aid from Vietnam and other socialist countries. However, these policies were not tenable over the ensuing years as the PRK needed many more resources to wage a protracted war against the Cambodian resistance forces mainly backed by China, the United States, and Thailand, feed the population, and contribute to the feeding of nearly 200,000 Vietnamese troops in Cambodia.

During the first two years (1979-80), the Vietnamese under the leadership of Le Duc Tho attempted to build an image of Vietnam as a selfless neighbor and friend in a time of need. But this image was short-lived. Tho was credited with saving the Cambodian people from starvation and laying the political and economic foundation of the PRK. But in February 1980 he was called back to Hanoi to assume more important party functions as a member of the Politburo.

In a Politburo meeting in November 1980, he spoke highly of the power of Vietnam's state bureaucracy and system, which enabled the party to achieve victory in two wars of aggression (waged by the Khmer Rouge and its patron, China) and fulfill its international duty to help build the Laotian and Cambodian revolutions.28 For the conservative leader Le Duc Tho, building the new socialist state in Cambodia not only eliminated the threat to Vietnam's national security in the southwest once and for all but also was part of the CPV's "export of its socialist model" to the new regime in Cambodia, dressed up in an "international socialism" suit.29 This justified Vietnam's all-out assistance to the new socialist regime in Cambodia. According to the first Vietnamese ambassador to the PRK, Ngo Dien, Tho single-handedly selected and formed the first group of leaders of the PRK in 1979-81. During this period, all major decisions were made by the Vietnamese and handed over to Party Secretary Pen Sovann, who then presented them to the party as the ideas of the Standing Committee. 

However, as I point out in the next chapter, the economically minded leaders were of the view that Vietnam as a poor country was not in a position to provide nonrefundable aid to Cambodia and Laos for long and had to form mutually beneficial economic relations with Cambodia and Laos under Vietnamese leadership.

General Le Duc Anh was also credited with the military victory in Cambodia in the first eighteen months after the invasion. Notably, from October 1979 to May 1980, Vietnamese troops achieved significant success in their dry-season offensives across the Cambodian frontline. They claimed to have driven 20,255 enemy combatants from the battlefield, confiscated 11,296 rifles of various kinds, destroyed the enemy's ability to regroup and reassemble its forces, and attempted to create two territories and two authorities in various battle zones. As a reward, the Politburo appointed Le Duc Anh commander in chief of all Vietnamese volunteers and specialists, both civilian and military.31 Now it was General Anh's turn to deliver a success during his tenure in Cambodia.

Under General Anh's leadership, building Cambodia's military capability was paramount as protracted guerrilla warfare had developed. As General Anh replaced Le Duc Tho at the helm of nation-building in Cambodia in late 1980, the military assumed more responsibilities and, simultaneously, vast power in Cambodia. This constituted a major shift from Le Duc Tho's mission, which focused on restoring basic livelihoods and building a revolutionary government.

At the district level from 1979 to 1980.32 Le Duc Anh continued Le Duc Tho's district fortification strategy, but this time it was the Vietnamese military leaders who called the shots. In 1981, General Anh ordered the withdrawal of economic and cultural specialists at the district level and ordered Vietnamese battalions stationed at each locality to defend the territory and strengthen Cambodian district authorities.

In August 1985, General Anh planned to create three to five local battalions for each Cambodian province, and he instructed the Vietnamese military to play an important role in assisting the PRK in building civilian authority at the local level. Cambodian and Vietnamese military leaders were to work jointly to establish each battalion. At first the ratio was one Cambodian combatant for every two Vietnamese soldiers. Over time the Vietnamese were to be phased out, leaving all responsibilities to the Cambodians.34 But initially the newly created battalions of revolutionary Cambodian armed forces were placed under the supervision of the general political department of the Vietnamese occupying force. For instance, in 1980 Division 302 of Military Region 7 swiftly helped build civilian authority in eight districts, seventy-one communes, and 1,360 villages; on the military side, it built nine companies consisting of 1,821 combatants and 2,840 commune militiamen and equipped them with 4,106 rifles. In addition, it helped local authorities build seven schools, forty-six headquarters for people's committees, and ten commune clinics. In the same fashion, every military division was deeply involved in this strategy as the Vietnamese drove Cambodian resistance forces toward the Thai border.35 The Vietnamese believed that this strategy would allow the PRK to control newly liberated territory and strengthen local revolutionary governments to cut off popular support from the Cambodian resistance forces.

To assert military control over Cambodia, on June 6, 1980, the Vietnamese MoD issued Resolution 62/CT-TM, creating a military command structure that gave each provincial military division a code name to mimic the three military regions (5, 7, and 9). In the second half of 1980, each military region was given total responsibility for civilian and military affairs in the region under its control. Each military region was tasked with helping its Cambodian counter- parts to establish and strengthen PRK commune and district authority, build local armed forces, maintain political order and security, distribute food and medicine, and help the Cambodian people return to their livelihoods.

General Anh was pleased with the progress over a short span of eighteen months. By mid-1980, the three military regions claimed to have reintegrated nearly 400,000 Cambodians who had left with the Khmer Rouge and gone to the Thai-Cambodian border, provided them with shelter and food, and restored their means of food production and their livelihoods.

On the military side, throughout the rainy season (May-October) of 1980, the Vietnamese army and the PRK armed forces together dealt a serious blow to the newly reinforced seven divisions of Cambodian resistance forces, forcing five divisions to flee across the Thai border. They then fortified a defensive belt stretching 740 kilometers along the border and strengthened their control over a number of strategic outposts, including Preah Vihear, Samroang, Nimit (Uddar Meanchey Province), Malai, Pailin, Samlot (Battambang Province), and Koh Kong Province (in the northwestern region of Cambodia bordering Thailand). Their main objective was to prevent the enemy from infiltrating from the Thai border. However, the success of these efforts would soon evaporate as the Cambodian resistance was able to rebuild its military power and strengthen its political standing with the help of China, the United States, Thailand, and their allies.

Growing Hostility between the Vietnamese Army and Local Cambodians

From 1981 to 1983, the Cambodian resistance employed a strategy of entrenched guerrilla warfare with the objective of controlling the jungle and mountainous regions, rural areas, and towns and cities surrounding river deltas.

From 1980 onward, a number of refugee camps were created along the Thai-Cambodian border, including at Anlong Veng (Uddar Meanchey Province); Preah Vihear Province; and Dang Rek, O' Da, Kamrieng, Malai, and Ta Sanh (Battambang Province). In these camps, the Khmer Rouge and its resistance allies received foreign aid, conducted military training supported by foreign specialists, and developed their armed forces.38 From these relatively safe bases, they launched raids against the Vietnamese and attacked convoys to cut off their food supply and break their will to fight in Cambodia. In early 1981, one-third of the Khmer Rouge forces penetrated undetected the interior of the country into the seven provinces along the Thai-Cambodian border. A large number of them surrendered and, according to the Vietnamese, became "two-faced enemies" hidden among the villagers, acting as spies for the Cambodian resistance or working against the Vietnamese at the local level. Some even infiltrated the local authorities.39 By 1982 the Cambodian resistance forces had gained control of large areas of Battambang, Siem Reap, Preah Vihear, and Stung Treng provinces. They would use these bases to expand their military offensives in the interior of the country.

From 1982 onward, the image of Vietnam as a nation-builder changed to one of an occupying force, and resentment crept into the Vietnamese-Cambodian fraternity. The Vietnamese commanders at the frontline began to harbor distrust 

toward the local Cambodian people and authorities. They became convinced that two-faced enemies with allegiance to the resistance forces were hiding among the general populace. The perception of being surrounded by enemy fighters and a hostile population at the local level created a siege mentality within the Vietnamese army in Cambodia.

By 1982 the Vietnamese military leadership in Cambodia, including General Le Duc Anh, had come to the conclusion that the resistance forces had already penetrated the Cambodian revolutionary authority and the general populace in order to conduct espionage, becoming a sort of Trojan horse to conduct military attacks, incite popular uprisings, plunder food supplies, and destroy the local economy.In a new phase of psychological warfare, Front 479 decided to elevate its three-pronged strategy combining military, political, and diplomatic efforts. It stressed the necessity of eliminating the two-faced enemies among the population and local Cambodian authorities. It also emphasized the importance of intensifying propaganda campaigns and mobilizing popular support to counter the enemy's psychological warfare.

Vietnamese convoys on National Road 5 passing through Siem Reap to the frontline were frequently ambushed by Cambodian resistance forces. According to one Vietnamese source, more than 30 percent of troops protecting convoys suffered casualties every year, forcing the high command to provide additional troops to protect the convoys, repair bridges and roads, and clear land mines.

In the rainy season of 1982-83, Cambodian resistance forces were able to launch raids into Vietnamese army camps, increasingly destroying economic foundations and exhausting the Vietnamese fighting capability throughout the frontline in the provinces of Battambang and Siem Reap, under the control of Front 479.43 The fact that many of these ambushes took place near villages or in town centers, combined with the Vietnamese perception of the threat posed by the two-faced enemies hiding among local Cambodian people and authorities, undoubtedly had a profound psychological impact on the Vietnamese troops. The command of Front 479 was under tremendous pressure to achieve Hanoi's objectives.

For many rank-and-file soldiers, a prolonged war seemed to make no sense as they faced an increasingly hostile local population. Nguyen Thanh Nhan, a Vietnamese veteran of Front 479, reflects in his memoir *Away from Home Season: The Story of a Vietnamese Volunteer Veteran in Cambodia*, “We weren’t like the soldiers of the years 1978–80. They fought to drive away Pol Pot’s cruel army that was burning and killing innocent [Vietnamese] people along the Vietnam-Cambodia border. They all absolutely understood the meaning and purpose of their jobs. They deserved to be called ‘volunteers.’ For us soldiers after 1980.

things weren't as clear and simple as that.44 Thanh Nhan's account reveals that many Vietnamese soldiers at the frontline in Cambodia questioned the whole notion of Vietnam's "noble mission" as they increasingly encountered hostility from Cambodian villagers who saw them as "occupiers."

However, the conduct of the Vietnamese toward the Cambodians contributed directly to their deteriorating relationship. Le Duc Tho's admonition to the Vietnamese was not carried out well in practice, especially in battle zones like Siem Reap Province. For instance, in the district of Chi Kreng, the relationship between District Chief Kham Sokhom and his Vietnamese adviser, Major Nguyen Van Bao, was one of "student-teacher," or "subordinate-superior," to use Kham's words. This was the standard practice throughout the battle zones in northeastern Cambodia. The Cambodian district chief was required to submit to the Vietnamese adviser a daily report on three important issues: the enemy's activities, food production, and local party affairs. On important issues like this, the Vietnamese adviser made decisions and instructed the district chief to execute them as he saw fit.45 In Major Bao's absence, Chief Kham was instructed to seek advice from his deputy, who was also a political commissar.46 The overwhelming presence of the Vietnamese army and military advisers dominated Cambodian authority in this region.

By 1982, as Cambodian resistance forces launched frequent raids and the Vietnamese suffered a growing number of casualties and loss of food supplies and equipment, the relationship between the Vietnamese military adviser and the district chief became increasingly strained. The deteriorating relationship between the Vietnamese troops and local Cambodian people worsened the already bleak situation. Food was in short supply for Vietnamese troops as deliveries were delayed due to the Khmer Rouge raids. Throughout 1982, villagers lodged complaints with the Cambodian authorities about Vietnamese soldiers' transgressions, from stealing chickens, dogs, pigs, cows, and vegetables to aggression against Cambodian women, including cases of rape. A cloud of fear hung over local villagers when Vietnamese troops moved in.47

Since 1979 when the Vietnamese first entered Cambodian territory, the issue of some soldiers' misbehavior had been brought to the attention of the Vietnamese government at that time. For instance, on May 29, 1979, a member of the Vietnamese National Assembly reported to the party and the government that "a small number of Vietnamese soldiers did bad things in Cambodia, and some Cambodian people have become suspicious of us. If this drags on much longer, it will erode the Cambodian people's trust in us."48 These misdeeds increased from 1981 onward, partly because Vietnamese soldiers in Siem Reap bore the brunt of the Cambodian civil war and, as Vietnamese newspapers describe, they were exposed to daily hardships such as nutritional deficiencies and malaria.49 They would stop villagers along the road or go to their homes to "ask for" things they lacked.

District chief Kham Sokhom recalled his fear of retaliation every time he reported villagers' complaints to his Vietnamese adviser. Feeling sympathy for the Vietnamese soldiers who endured so much hardship and risked their lives in Cambodia, he chose to ignore some trivial issues.50 In Kham's recollection, such misconduct by Vietnamese soldiers caused the villagers to harbor resentment and fear of the Vietnamese and to become sympathetic to the Cambodian resistance, including the Khmer Rouge. Villagers who in 1979 saw the Vietnamese soldiers as their saviors from the genocide later became sympathizers of the Cambodian resistance.51 Some sent their sons to join the resistance, while others provided food and shelter to the resistance fighters and spied on the Vietnamese to help their cause.52 In effect, this fed the Vietnamese suspicion of the two-faced enemy hiding among the populace, resulting in a cycle of mistrust and misunderstanding between the Vietnamese military and the local population. Eventually, the Vietnamese occupying forces took steps to purge Cambodian officials suspected of supporting the resistance. 

In his memoir, Nguyen Thanh Nhan recounts the following conversation between a Vietnamese soldier, Huy, and his superior, Quan, at a Cambodian wedding ceremony in a village adjacent to their camp that captures the Vietnamese soldiers' mistrust mixed with frustration with Cambodian villagers.

"The villagers are so kind and simple, aren't they?" Huy asked Quan.

"Most of them are like that," Quan answered.

"But in our unit, there are some guys who don't like them. They say that the villagers are just pretending to like us, because they're all enemies. They ask how anyone who has children and relatives who followed Pol Pot could like us, Vietnamese soldiers. Our friend Thien treats the villagers as his enemy. He's always suspicious of them and looks down on them."

Quan answered, "Some Vietnamese soldiers actually like the Cambodians, but some befriend them only to take advantage of them, and consider them fools and inferior. The minds of such men are full of prejudice and discrimination against people of other colors and races."

Huy said, "I think that for anybody of any nation or race, if other people treat him kindly, he certainly has to treat them the same. Isn't it better to be good and honest with everyone, brother Quan?"

Quan replied, “It's easy to say that, but it's not easy to do, Huy. It's noble of you to think like that, but sometimes we do the right thing to help people, but all we get in return is misunderstanding and hostility.”

According to Chief Kham, local villagers' distrust of and resentment toward the Vietnamese reached an all-time high after news of the arrest of Prime Minister Pen Sovann, who was in office for a little more than five months, in December 1981 reached the general populace. Pen Sovann was widely known as a staunch nationalist, especially among residents of Kampong Khleang, a fishing village located on Siem Reap's Tonle Sap Lake. Cambodian fishermen had been

complaining about the influx of Vietnamese fishermen and saw the arrest as an attempt by the Vietnamese to assert their colonial control over Cambodia. After Pen Sovann's arrest, fear and mistrust replaced gratitude toward the Vietnamese in the minds of many state cadres. 

The Campaign against the “Two-Faced Enemy” in Siem Reap

Beginning in the summer of 1982, there were reports of people who worked for the government of Cambodian leader Heng Samrin during the day and for Pol Pot at night. In April 1983, as fear of enemy infiltration into Cambodian local authorities ran high in Siem Reap Province, the Front 479 command received what it believed to be “concrete evidence” warranting a crackdown on the two-faced enemies among the people and the entire Siem Reap authority. The evidence came from a confession by a deputy head of a Khmer Rouge regiment who defected to the Vietnamese.58 Such events likely confirmed Front 479’s belief that it had to hasten the arrest of local officials before they had a chance to escape.

The perceived and real two-faced enemy compelled the Vietnamese leadership to take drastic measures, and the pressure to succeed became even greater for local Vietnamese commanders at the frontlines in Cambodia. On January 20, 1983, the Central Military Commission issued resolution 05/NQ-QU regarding military duty in Cambodia. It stressed the “urgent need” to strengthen the ability of the Cambodian armed forces to “undertake major responsibility for combat along with Vietnamese troops, independently manage their armed forces, and assume greater control over the liberated zones.” The resolution underscored the necessity of launching major military offensives against the enemy and eliminating the two-faced enemies among the population and local authorities.60 Under these conditions, the Vietnamese military leadership began to sidestep the principle of equality and noninterference with the Cambodian government and engaged in what Huy Duc,61 a Vietnamese veteran in Cambodia, called “big-country chauvinism” (tu tuong dan toc nuoc lon).

What happened next was a terrifying campaign of arrest, interrogation, and torture of Cambodian officials in Siem Reap Province in 1983. In that year, the Vietnamese military in Siem Reap arrested several hundred suspected resistance sympathizers, including district and provincial officials and security officers.63 In April at least forty Cambodian officials—most of whom had received lengthy political training in Vietnam and were installed in these positions by the Vietnamese themselves—were arrested, and the governor of Siem Reap Province committed suicide when Vietnamese military officials came to arrest him.64 These events sent a shock wave through Cambodia. Some officials who feared arrest fled into the jungle. Many of those who were arrested were detained in Vietnamese military barracks to await interrogation, and some were tortured when they refused to confess to aiding the resistance.65 The purge prompted thousands of Cambodians to head for the border, many of them arriving at the refugee camps accusing Vietnam of “colonialism.” 

A First-Person Account of the Purge

Kham Sokhom, chief of the district of Chi Kreng in Siem Reap Province, became one of the victims of the purge by Front 479. Between 1980 and 1982, Kham received political training in Thu Duc (Ho Chi Minh City) on three occasions and was promoted from commune chief to district chief after he completed his first political studies in Thu Duc in 1980. He was one of many Cambodian officials in Siem Reap Province who were arrested for the alleged crime of working or spying for the Cambodian resistance forces. In other words, he was accused of being a two-faced enemy who had infiltrated the PRK regime. In 2016 Kham recounted the story of his arrest and torture by the Vietnamese, and I will summarize it as follows:

One morning in May 1983, Kham Sokhom left home in Prasat village (Kampong Kdei subdistrict, Chikreng district, Siem Reap Province) for his office in a small town in Kampong Kdei subdistrict. At eight o'clock his Vietnamese adviser, Major Nguyen Van Bao, summoned him to an adjacent room for a routine meeting. Major Bao asked Kham, “Do you know about the arrest of Cambodian provincial officials in Siem Reap?” Kham replied, “Yes, I heard about it. Why?” Without replying, Bao told Kham to wait in the room and left. At the same time, six other district officials were being questioned in different rooms of the district headquarters.

Two Vietnamese soldiers came to stand guard at the door of the room where Kham was held. A Vietnamese military officer entered the room, instructed the guards to confiscate all of Kham's belongings, and gave Kham a pen and three sheets of paper with which to write his revolutionary autobiography. Accused of secretly colluding with the Khmer Rouge enemy, Kham was placed under arrest and detained in the district office. The next day he was told to write a self-criticism report about his antiparty and anti-Vietnamese activities. But he wrote nothing, instead telling the Vietnamese officer that he had done nothing wrong.

On the third day, the Vietnamese officer threatened to send Kham to the regional Vietnamese military headquarters for interrogation if he refused to confess his secret collusion with the Cambodian resistance. Again Kham declined to write a confession. The officer said to him, "A lot of our soldiers were killed in your district. How come you don't know anything?" That night two Vietnamese army trucks arrived at the district headquarters. Kham was blindfolded and thrown into one of the trucks. Locked in a military prison inside the Vietnamese army compound, he was about to face a harrowing ordeal that would last for three weeks.

Kham was shackled to the floor in an isolated makeshift hut and guarded at all times. For the first three days he was told, "If you write your confession, we might consider reducing your punishment, but if you refuse, you will certainly die." Every day two guards walked him blindfolded around the military camp, occasionally firing shots to frighten him before he was sent to an interrogation room. On the seventh day, at midnight, he was transferred to a smaller bamboo hut, which he called a "chicken cage" because of its small size. Day in and day out, he was harangued to confess his reactionary activities. On the tenth day he was threatened with transfer to a harsher prison in Phnom Penh. Yet he still refused to admit any wrongdoing.

On the twenty-first day of his captivity, at about nine o'clock in the morning, Kham was taken to a room that was somewhat nicer than his prison cell. He heard a helicopter arriving at the camp. Minutes later a man who appeared to be a ranking leader arrived with an entourage of twelve military officers.

"Just talk," he told Kham. "No need to write anything. Just talk about your antiparty activities and I will reduce your punishment."

Kham replied, "I was chosen by the Vietnamese army to lead my people. I was trained by the Vietnamese, and I speak Vietnamese. Why would I betray my Vietnamese comrades?"

The interrogator pointed out, "Pol Pot speaks Vietnamese fluently and even fought side by side with us, but he still betrayed us."

Kham answered, “I helped my people, and the record shows that I called on thousands of people to defect from enemy territory.”

The interrogator smiled and said, “Then I’ll send you to the Phnom Penh prison.” He ordered Kham to put on a suit and tie to be photographed. As the Vietnamese photographer was about to take his picture, the interrogator said, “Don’t forget to smile!” Kham replied, “I can’t smile. I’ve had little sleep for three weeks.”

After the photograph was taken, the interrogator banged his fist on the table and shouted, “We treated you well but you refuse to confess. You show no fear. Why aren’t you afraid?”

Kham replied, "Because I've done nothing against the party."

The interrogator turned to the guard and said, “Ask him if he's right- or left-handed." When Kham answered that he was left-handed, the guard tied his left thumb behind his back with a rope slung over a wooden beam above him and

began to pull him up by his thumb while the interrogator was forcing him to

confess. The interrogator warned, "This is your last chance to confess." Kham

replied, "I am innocent." Through a fog of pain he heard the interrogator remark, "He's honest." Kham soon lost consciousness from the pain. When he gained consciousness, the interrogator had already returned to the helicopter awaiting him in the military compound and left.

Two days later Kham was released and summoned to meet a visiting representative of the CPV in the city of Siem Reap. He did not know at the time that the head of the eight-member delegation was Politburo member Chu Huy Man, Hanoi's top party official. In addition to an apology for what happened, Kham was given gifts of a bottle of Russian vodka, a case of crackers, two tea bags, a box of instant noodles, and 500 riels (roughly US$250) in cash. He continued to serve as chief of Chi Kreng district for the next two years. He was offered a promotion to a judiciary position in the Siem Reap provincial administration. He accepted it but resigned two years later in 1985.

The Vietnamese Response to the Purge

When news of the arrests and torture in Siem Reap reached Hanoi, the Politburo of the CPV became deeply concerned about the political and military ramifications of the event. Prime Minister Pham Van Dong was furious and called on the Politburo to punish the commanders of Front 479, which had direct oversight over the provinces of Siem Reap and Battambang, and Command 719, which was in charge of the entire VVA in Cambodia.68 The Siem Reap incident involved forced confessions and torture of Cambodian officials under the command of Front 479. Ngo Dien, the first Vietnamese Ambassador to the PRK at that time, recalled, “The arrests, coercion, and torture caused the unjust death of many [Cambodians] It was so bitterly painful when I heard the Cambodian public and officials ask, ‘Why did the Vietnamese officials do something like this?’”

Vietnamese military's authority. The Politburo's investigation revealed that the Vietnamese military in Siem Reap had exceeded its authority and engaged in behavior that damaged Vietnam's reputation in Cambodia.69 The Politburo concluded that the Vietnamese military had violated the principle of noninterference in the internal affairs of Cambodia and had abused its power. The Politburo ordered the immediate release of all Cambodian officials who had been wrongfully arrested and punished the Vietnamese commanders responsible for the abuses.

The Siem Reap purge was a turning point in the history of the Vietnamese occupation of Cambodia. It marked the end of the initial honeymoon period between the Vietnamese and the Cambodian people and the beginning of a period of growing disillusionment and resentment. The Vietnamese military's heavy-handed tactics and disregard for Cambodian sovereignty alienated many Cambodians and fueled support for the Cambodian resistance. The purge also exposed the limitations of the Vietnamese model of nation-building in Cambodia, which was based on a top-down approach and the imposition of Vietnamese values and practices on the Cambodian people.

In the aftermath of the Siem Reap purge, the Vietnamese leadership sought to distance itself from the actions of its military commanders in Cambodia. Hanoi began to emphasize the importance of a more nuanced approach to nation-building in Cambodia, one that was more respectful of Cambodian culture and traditions. However, the damage had already been done. The Vietnamese occupation of Cambodia would continue for another decade, but it would be a decade marked by increasing resistance and instability.

Huy Duc, the former Vietnamese military specialist who served in Cambodia in 1983, later interviewed a number of retired Vietnamese leaders. He asserts in Ben Thang Cuoc that before the "Siem Reap case" (vu Xiem Riep in Vietnamese), some top officials of the PAVN were well aware of what Front 479 was about to do.72 Coincidentally or not, when the purge was carried out, General Le Duc Anh, commander in chief of all Vietnamese volunteers in Cambodia, was in the Soviet Union for eye treatment. Confronted with this politically sensitive matter, Le Duc Tho sent a telegram on behalf of the Politburo recalling General Anh to Vietnam to deal with the problem.73 General Anh recalled in his memoir, "I returned to Hanoi, and the Politburo called a meeting to discuss this incident. At the time, Brother To [Prime Minister Pham Van Dong] expressed strong criticism and proposed heavy punishment for all officials of Front 479 and Command 719 who were involved in this incident."75 However, General Anh proposed to the Politburo that only those high-ranking officials of Front 479 and Command 719 who were directly involved in the incident be disciplined. According to General Anh, General Ho Quang Hoa, his deputy, came to Hanoi to ask for instructions from the upper echelon. There is no direct evidence to indicate that General Hoa received a tacit order from Hanoi's leaders. However, General Anh did not reveal which officials were briefed and who issued the order for the purge in Siem Reap. General Anh made no attempt to identify the senior leaders in question, preferring instead to put the blame on a few Vietnamese generals in Front 479, and therefore he left it to the Politburo to determine the responsibility of upper-echelon leaders.

No available evidence specifically names those leaders, but in all probability the purge in Siem Reap was carried out with the knowledge of the Department of Political Affairs of the MoD, if not the minister of defense (General Van Tien Dung) himself. General Anh, who was put in charge of the investigation, knew that it was beyond his power to pursue those military leaders. Nevertheless, the Politburo accepted General Anh's proposal to discipline a few local commanders and dispatched General Chu Huy Man, a Politburo member and chairman of the General Political Department of the PAVN, to Phnom Penh to offer an official apology to the PRK party and the government of Cambodia. General Anh ordered the leadership of Front 479 to immediately release all Cambodian detainees and cease all interrogations and physical abuse. He ordered all relevant departments of Front 479 and Command 719 to submit "situation reports" to him. General Anh recalled in his memoir, "At the beginning of my investigation], some comrades did not understand and called me 'a traitor.' And some even shifted blame to the Hanoi leadership because they said they had already asked for instructions from Hanoi' before they took such extreme measures." 

The Siem Reap purge marked a turning point in the history of the Vietnamese occupation of Cambodia. It exposed the limitations of the Vietnamese model of nation-building in Cambodia, which was based on a top-down approach and the imposition of Vietnamese values and practices on the Cambodian people. The Vietnamese military's heavy-handed tactics and disregard for Cambodian sovereignty alienated many Cambodians and fueled support for the Cambodian resistance. In the aftermath of the Siem Reap purge, the Vietnamese leadership sought to distance itself from the actions of its military commanders in Cambodia. Hanoi began to emphasize the importance of a more nuanced approach to nation-building in Cambodia, one that was more respectful of Cambodian culture and traditions. However, the damage had already been done. The Vietnamese occupation of Cambodia would continue for another decade, but it would be a decade marked by increasing resistance and instability.

After his investigation in Ho Chi Minh City and Cambodia, Anh came to this conclusion: "Our [Vietnamese] comrades did not have any ill intention or harbor revenge against the Cambodian officials [in Siem Reap], but premature evidence and excessive hastiness led to these mistakes.... It would not have been right if we did not discipline some officials, but it would not have been right to impose heavy discipline either." According to General Anh, in May 1983, the Front 479 command depended on unverified sources for its analysis and concluded that in June 1983 there would be an uprising in Siem Reap Province, that the enemy controlled the Cambodian revolutionary authority in the province, and that 80 to 100 percent of the people, the number varying from  place to place, supported the enemy.⁷⁹ Thus the official narrative, according to General Anh, attributed the Siem Reap purge to "an error in judgment and the unwarranted hastiness of local military commanders of Front 479," thereby protecting the upper echelon in Hanoi from accusations of wrongdoing. 

In the end, two military officials were disciplined. Ho Quang Hoa, deputy commander of Front 719, was demoted from general to colonel and removed from the Central Committee of the CPV, a position he was elected to in March 1982. General Le Thanh, commander of Front 479, was demoted to the rank of colonel. When General Le Duc Anh reported back to the Politburo, Prime Minister Pham Van Dong remarked, “Dealing with the issue this way is good. And such internal disciplinary action is correct!”81 In addition to an official apology to the PRK Politburo, General Chu Huy Man led a party delegation from Hanoi to visit families of Cambodian officials who were wrongfully arrested and present them with gifts. As General Le Duc Anh recalled, the PRK Politburo told Chu Huy Man, “The shortcomings are not worthy of mention because Vietnamese comrades sacrificed the flesh and blood of tens of thousands of Vietnamese soldiers and specialists to rescue the Cambodian people from the genocide and reconstruct our country.”82 This obsequious attitude reflects the PRK leadership’s inferiority to and dependence on the Vietnamese leadership imposed by the powerful conservative leader Le Duc Tho from the heyday (January 1979) of the PRK regime. As his memoir reflects, Vietnamese ambassador Ngo Dien, who was a close adviser to then foreign minister Hun Sen, must have been disheartened by the purge as he was trying to show the world  that Vietnam respected Cambodia's national sovereignty. According to Ngo Dien, "The origins of the Vietnamese mistakes like the 'Siem Reap case' was rooted in tu tuong dan toc nuoc lon [the nationalist ideology of a big nation], and the obvious evidence of this ideology was the fact that we [the Vietnamese leaders at that time] assigned ourselves the role of rearranging the Cambodian revolution."

The Aftermath of  the Purge

The long-term effects of the purge perpetuated the Cambodian people's distrust of the Vietnamese and beyond toward Vietnam. According to Ambassador Ngo Dien, the villagers' terror and anger toward Vietnam spread to the entire province of Siem Reap and then quickly to the entire country.

Just two years after the Siem Reap arrests, in May 1985, another shocking incident took place in the village of Kandal in the Svay Chek district of Battambang. This time, a Vietnamese soldier from a public relations battalion stationed in the area raped a young Cambodian girl in front of two other girls and elderly villagers on the outskirts of the village. He then shot his victim and those who tried to flee the scene, killing five innocent Cambodian women. 

The village was outraged and called for revenge. This terrifying news spread like wildfire. To appease the villagers, the military court of Front 479 condemned the Vietnamese soldier to death after a public trial.87 In a public statement, the court declared, "The Front Military Court sentences the accused to death for his savage murder of many innocent Khmers, which has driven a wedge between the soldiers and people of the two countries and destroyed the Vietnamese army's honor and prestige.... We would like to ask for your forgiveness. There were always short and long fingers on our hands."88 The Vietnamese essentially explained to Cambodian people that these were just misdeeds committed by a few men in the anti-Vietnamese army. To the Cambodian people, mindful of their long history of anti-Vietnamese resistance, such incidents happened too often and fueled their fear and distrust of the Vietnamese. Their gratitude for Vietnam's liberation of Cambodia evaporated quickly when these incidents continued unabated.

The extent of the purge shocked the Cambodian populace and played into the hands of the Coalition Government of Democratic Kampuchea, in short the Cambodian resistance. Its contagious effects significantly undermined Hanoi's twin objectives of "continuing to win the trust of the Cambodian people and bring about mass defection of the enemy forces,"89 as the Vietnamese Ministry of Foreign Affairs expressed it.

These incidents played into the Cambodian populace and played into the hands of the Cambodian resistance, especially the Khmer Rouge, which was able to exploit these incidents to portray the Vietnamese as brutal occupiers. The Vietnamese military's high-handed tactics and disregard for Cambodian sovereignty alienated many Cambodians and fueled support for the Cambodian resistance. In the aftermath of the Siem Reap purge, the Vietnamese leadership sought to distance itself from the actions of its military commanders in Cambodia. Hanoi began to emphasize the importance of a more nuanced approach to nation-building in Cambodia, one that was more respectful of Cambodian culture and traditions. However, the damage had already been done. The Vietnamese occupation of Cambodia would continue for another decade, but it would be a decade marked by increasing resistance and instability.

• The long-term legacy of the Vietnamese occupation of Cambodia is complex and multifaceted. It has left a lasting impact on the Cambodian people, who continue to grapple with the trauma of the Khmer Rouge genocide and the Vietnamese occupation. The Vietnamese intervention in Cambodia is a cautionary tale about the dangers of foreign intervention and the importance of respecting the sovereignty of other nations.

The souring relationship between the Vietnamese troops and local people tipped the psychological warfare in favor of the Cambodian resistance forces, unleashing deadly consequences for Vietnamese soldiers who passed through rural villages and making it difficult for the public relations units of Front 479 to win the hearts and minds of the local people after 1985.90 To further drive a wedge between the Vietnamese troops and Cambodian villagers, the resistance forces often launched surprise attacks on villages through which Vietnamese troops were passing or in which they were temporarily stationed. As a result, many villagers fled their homes when the Vietnamese arrived. The resistance forces rewarded villagers who concealed their agents or spied on the Vietnamese. 

To the Cambodian people, the Siem Reap purge of local officials in 1983 definitively marked the beginning of the end of Vietnam's moral high ground and claim to have respect for Cambodia's national sovereignty, which in turn tilted the psychological warfare in favor of the resistance forces. Even before the Vietnamese invasion of Cambodia in December 1978, the Vietnamese leaders, including Prime Minister Pham Van Dong, warned of the danger of Vietnamese chauvinism toward their Cambodian comrades, and yet military victory on the Cambodian battlefield was a priority, and other political and economic issues were considered secondary. Consequently, the Vietnamese occupying force's mistreatment of Cambodian civilians and officials was not properly addressed by the top Vietnamese leadership. The VVA and the advisers themselves ended up being seen by the Cambodian populace and local cadres as occupiers instead of liberators.

The Vietnamese mission in Cambodia during the early years 1979–83 evolved from saving the Cambodian people from genocide and preventing mass starvation after toppling the Pol Pot regime to full-fledged nation building. This was achieved by exporting Vietnam’s experiences with revolution and building socialism to Cambodia, oddly enough a country with a very different culture and a long history of anti-Vietnamese nationalist sentiment. As the Cambodian resistance grew with the increased support of China, the United States, and ASEAN—particularly Thailand—Hanoi’s strategy emphasized military victory over the resistance forces more than political correctness, that is, respecting Cambodia’s sovereignty and noninterference in its internal affairs. The arrest of the first PRK prime minister, Pen Sovann, in 1981 and subsequent purges in Siem Reap are symptomatic of Vietnam’s “big-country chauvinism,” which fed Cambodia’s traditional fear of Vietnam’s southern expansion at its expense.

As leadership of Vietnam's nation-building mission in Cambodia passed from Le Duc Tho to General Le Duc Anh after 1981, operational power also shifted from intellectual and civilian committees like B68 and A40, which were in charge of military affairs and economic and cultural affairs, respectively, to the supreme command of the Vietnamese occupying army in Cambodia. Reports from Cambodia were often glowing until the Siem Reap purge incited overt Cambodian anger toward the Vietnamese. The Vietnamese military's heavy-handed measures to get rid of perceived and real two-faced enemies in Cambodia caused the goodwill and moral capital earned during 1979-80 to evaporate quickly. In retrospect, from the vantage point of political and psychological warfare in Cambodia, General Le Duc Anh's emphasis on a big military victory on the battlefield to quickly strengthen PRK control was counterproductive, causing the blowback effect of growing anti-Vietnamese sentiment toward Vietnamese soldiers in Cambodia.

The purge is an example of large-scale “moral self-licensing,” under which the commanders of the Vietnamese occupying forces in Cambodia justified and ignored immoral acts committed by their officers based on Vietnam’s immense sacrifice for Cambodia. To this point, the first Vietnamese ambassador to the PRK, Ngo Dien, attributed the purge to ethnocentric superiority embedded in big-country chauvinism and manifested in Vietnam’s self-proclaimed “role of forging the Cambodian revolution from start to finish.” Vietnam's military commanders, however, including General Le Duc Anh, rather than considering their officers' and soldiers' conduct as emblematic of a larger offense against the Cambodian people's trust, cast these problems as isolated incidents or random mistakes and concluded that disciplining a few officers would be sufficient. A few top Vietnamese leaders, such as Prime Minister Pham Van Dong, Le Duc Tho, and Ambassador Ngo Dien, recognized the costly political and diplomatic fallout. But the Vietnamese military leadership in Cambodia believed that it had a moral license to conduct the purge. As Vietnamese veteran Huy Duc keenly observed, “Over the period of ten years [1979–89], the Vietnamese soldiers did a great deal to prevent the return of the Pol Pot regime. Many made the ultimate sacrifice of flesh and blood in Cambodia. At the same time, however, the Vietnamese leaders also interfered significantly in the decisions of the Cambodian government.”