Viet Nam has historically posed a threat to Cambodia’s national security, a threat manifested in forms ranging from interference in Cambodia’s internal affairs to military occupation. The Khmer Republic, for example, encountered serious threats from Viet Nam, particularly the Democratic Republic of Viet Nam (DRVN). On 21 January 1971, DRVN forces launched a surprise military attack on Cambodian soldiers at Phnom Penh airport, damaging several of the Lon Nol government’s aircraft. In 1970, North Viet Nam had already started interfering in the Khmer Republic’s internal affairs by aiding a Cambodian military faction known as the Communist Party of Kampuchea (CPK). CPK forces eventually overthrew the Khmer Republic government in April 1975. The Khmer Republic’s successor – Democratic Kampuchea (DK) – faced a similar fate; the DK government was toppled by the Vietnamese military in 1979.
On the contrary, since the Cambodian People’s Party (CPP) assumed full control of the government in 1998, Cambodia has enjoyed peaceful relations with Viet Nam. Specifically, Cambodia’s security has been greatly ensured vis-à-vis the latter. Hanoi has committed to respecting Cambodia’s independence and territorial sovereignty. Resolution VIII of the Central Committee of the Communist Party of Viet Nam, dated July 2003, emphasised that the top priority of Viet Nam’s external relations was to strengthen relations with neighbouring countries, including Cambodia. Viet Nam’s contemporary foreign policy towards Cambodia has been based on the ‘sixteen golden words’ principle: “friendly neighbours, traditional friendship, comprehensive cooperation, and long-term stability”. Thus, Hanoi officially has committed to building good relations and peaceful ties with Phnom Penh.
Cambodia’s exposure to different security experiences gives rise to important questions: What foreign policy did Cambodia embrace during the Khmer Republic and the Democratic Kampuchea? What type of foreign policy has the current government adopted to ensure its security in relations with Viet Nam since 1998?
II. Cambodia’s Past Foreign Policy towards Vietnam
Marshal Lon Nol established a republican form of government, the Khmer Republic, and adopted two forms of balancing strategies – soft and hard – in relation to the Democratic Republic of Viet Nam and the Republic of Viet Nam. In terms of soft balancing, Cambodia chose to completely align with the US; as for hard balancing, Phnom Penh opted for military confrontation against its larger neighbours, the Democratic Republic of Viet Nam in particular.
1.1. Soft Balancing
In terms of soft-balancing, the Khmer Republic embraced a policy of alignment with the US, as demonstrated through a series of events. In April 1970, Lon Nol publicly announced that, “Due to the gravity of the current situation, it is imperative to accept, from now on, all external assistance, from whatever sources, for the sake of the nation’s security”. The external assistance, in this regard, was mainly from the US.
Lon Nol’s handling of power-sharing with his domestic opponents also reveals the general’s policy of alignment with the US. During the visit by US Vice-President Spiro Agnew to Phnom Penh in 1973, Lon Nol was asked to share power with his opponents, including In Tam and Sirik Matak. He yielded to American pressure and began sharing power with them. Lon Nol’s request for collaboration with his opponent, Sirik Matak, illustrated Lon Nol’s bandwagoning policy with Washington. Sirik Matak asked why Lon Nol had wanted to meet with him and another rival, In Tam. Lon Nol responded that, “Our foreign friends, who provide so much aid, have asked me to reconstitute the 1970 government.” Lon Nol did not further elaborate the reasons for acquiescing to the American suggestion, but simply offered Sirik Matak the vice-presidency. It is worth noting that Lon Nol and Sirik Matak had been partners when Sihanouk was in power. After Sihanouk was deposed in 1970, Lon Nol tried to centralise all power into his own hands, pushing Sirik Matak into opposition.
The Lon Nol government even backed the US bombing of Cambodia, although it caused severe casualties among Cambodian civilians. According to David Chandler, Lon Nol considered the US bombardment as a deus ex machina for Cambodia, and even requested the US to continue the bombardment indefinitely. US B-52s dropped approximately 540,000 tons of bombs on Cambodia during the Khmer Republic’s years in power (triple the amount used by Allied Forces against Japan during World War II), inflicting between 150,000 and 750,000 casualties. The bombing came to a halt only at the insistence of the US Congress in August 1973. Following the US Congress’s resolution, and after US General Alexander Haig informed Lon Nol about the US’s inability to provide further military support for his regime against the communists (both Vietnamese communists and the Khmer Rouge forces), Lon Nol reportedly burst into tears.
1.2. Hard Balancing
The Khmer Republic also adopted a hard balancing approach in relations with both the Democratic Republic of Viet Nam (DRVN) and the Republic of Viet Nam (RVN). Specifically, the Khmer Republic flexed its military muscle against both North and South Viet Nam. In relations with North Viet Nam, the Lon Nol government initiated two major military offensives, in August 1970 and August 1971. Though the DRVN troops created bases inside Cambodia, Lon Nol ordered his military to carry out a major military attack (called Chenla I) in August 1970 with the aim of recapturing the lost territories, especially those in the east. Strategically, Lon Nol sought to open up a road link from Phnom Penh to the eastern town of Skoun in Kampong Cham province. Lon Nol’s war against the DRVN soldiers on Cambodian soil, however, ended up in a stalemate. Lon Nol could not regain control of the eastern territory from the communist forces as he had set to do. Nevertheless, the General regarded Chenla I as a success and hosted a series of victory celebrations in the capital.
Having convinced themselves of victory, the Lon Nol government became careless about possible counter-attacks. On 21 January 1971, the North Vietnamese army launched a surprise attack on the Pochentong airport, destroying the majority of the airplanes, including the country’s MiG fighter jets. This setback, and the failure of the Chenla I operation, did not, however, hold Lon Nol back from again using the military against North Viet Nam. In late August 1971, Phnom Penh carried out its second major military offensive, Chenla II, against the North Vietnamese in retaliation for the surprise attack in January. As Elizabeth Becker notes, Lon Nol emotionally declared that it was time to “take an eye for eye, a tooth for a tooth.” The fighting lasted about three months, ending on 6 December 1971 with heavy losses inflicted on the Cambodian forces. According to Becker, Lon Nol’s remaining soldiers — numbering around 50,000 men — were almost destroyed as an organisation, and approximately 3,000 troops (roughly 10 battalions) lost their lives.
In the meantime, hard-balancing also manifested in the Khmer Republic’s handling of relations with South Viet Nam. Despite the fact that Khmer Republic and the Republic of Viet Nam were both allies of the US, the Khmer Republic opted for military means to create tension with the Republic of Viet Nam. For example, in early April 1970, Lon Nol ordered soldiers to create detention camps to hold all Vietnamese citizens, regardless of their residence status. The Khmer Republic government acknowledged that it had arrested about 30,000 Vietnamese and imprisoned over 7,000.
The campaign to arrest all Vietnamese escalated into a pogrom in which many Vietnamese civilians were killed by Lon Nol’s forces. For instance, on 10 April 1970, eighty-nine Vietnamese were executed by Cambodian soldiers, with the massacre reported throughout the country and taken up by the international press. Even the US Embassy in Phnom Penh sent its protest to the General. Lon Nol’s harsh treatment of the Vietnamese also upset the Republic of Viet Nam, as several victims of the pogroms were supporters of the South Vietnamese government, not the communists.
Additionally, Phnom Penh accused RVN soldiers of stealing valuables in the Cambodian province of Kampong Cham, and Lon Nol’s troops engaged in fighting with RVN troops in September 1970. Lon Nol’s actions were, according to a respected anti-war group in the US, so harsh that its government may have faced the possibility of being overthrown by the Republic of Viet Nam had the communists not taken over Saigon.
Democratic Kampuchea (DK) chose the most extreme policy of hard balancing against its larger neighbour. The Khmer Rouge opted for direct military confrontation with Viet Nam, even though its forces were significantly inferior to the latter’s. The DK also sought to upgrade its military capability to match its more powerful neighbour by importing military equipment from China. In addition, DK chose to create a military alliance with China in order counter Viet Nam, which was militarily reunified in April 1975 and politically reunified as the Socialist Republic of Viet Nam the following year.
2.1. Military Offensives
In a surprising move, the Democratic Kampuchea government – despite its military inferiority – launched its first major attack on Viet Nam on 30 April 1977. DK forces began attacking villages and towns in the An Giang and Chau Doc provinces of southern Viet Nam, burning houses and murdering hundreds of Vietnamese civilians. The Khmer Rouge subsequently launched further offensives in Viet Nam in May, June, July and September 1977. The Vietnamese proposed negotiations with the Khmer Rouge, but the proposal was flatly refused. The DK mobilised up to two army divisions in the border areas close to Tay Ninh, and these forces engaged in fighting against Viet Nam in May 1977.
The DK government’s preference for the use of force against Viet Nam was clearly demonstrated in a resolution adopted by the top Khmer Rouge cadres in Cambodia’s Eastern Zone during a secret meeting on 27 July 1977, a copy of which later fell into Vietnamese hands during a military incursion into Cambodia. The resolution urged Khmer Rouge combatants to be ready to fight against the Vietnamese right into Vietnamese territory:
We must not only stop them and annihilate them on our territory…but must cross the border to stop them and annihilate them right on their territory. This is intended to cause more difficulties to them and to increase their fear of us. Then, after some time, they will no longer dare invade our country, and it will be their turn to strive to resist us.
The Khmer Rouge once again invaded Viet Nam on 24 September 1977, again murdering hundreds of Vietnamese civilians, including women and children. In December 1977, the border conflict between Viet Nam and Cambodia escalated further. This time, Hanoi decided to launch a large-scale invasion of the ‘Parrot’s Beak’, the province of Svay Rieng protruding slightly into southern Viet Nam, using warplanes, artillery and approximately 20,000 men. The superior Vietnamese army inflicted a major defeat on Democratic Kampuchea forces. In early January 1978, Vietnamese troops pulled out from the Parrot’s Beak, with Hanoi reckoning that the display of force would bring the militarily weaker DK to the negotiation table. This Vietnamese calculation, however, proved wrong. The DK leaders continued attacking Vietnamese territory.
2.2. Military Capability Upgrade
Apart from proactively launching armed offensives, Cambodia upgraded its military capability to match that of the Vietnamese. In early 1978, for example, the DK attempted to match Vietnamese military power by obtaining Chinese military hardware including 130mm and 150mm artillery pieces and MiG-15 fighter jets. In March 1978, Cambodia imported a radar-based anti-aircraft defence system from China, and in May it also received a considerable numbers of tanks, armoured vehicles, and long-range guns from Beijing in order to counter the Vietnamese troops.
2.3. Military Alliance with China
Democratic Kampuchea’s hard balancing against Viet Nam was additionally illustrated by Cambodian Foreign Minister Ieng Sary’s visit to Beijing in March 1977, during which he reportedly requested China’s military support. Nayan Chanda notes that Sary was welcomed by Chinese Vice-Premier Li Xiannian at a banquet where General Wang Shangrong was also present. Viet Nam was, according to Nayan Chanda, concerned about the presence of General Wang, who was a deputy chief of the General Staff of the Chinese Army, whose presence hinted at possible military cooperation or an alliance between Cambodia and China. Sary visited Beijing again in March 1977, reportedly to seek Chinese support against Viet Nam.
Beijing began showing support for the Khmer Rouge regime, which was interpreted by Phnom Penh as approval of its armed attacks against Viet Nam. At a banquet in Beijing on 17 April 1977, Chinese Foreign Minister Huang Hua praised the Khmer Rouge for successfully destroying foreign and internal enemies. He also reportedly assured the Khmer Rouge government that Beijing would adhere to Mao Zhedong’s foreign policy line to ally with small states against large power subversion, interference, or bullying. Hua added that, in the future, the Chinese and Cambodian peoples would forge closer ties, fight shoulder to shoulder, and advance together along the path of their common struggle.
Democratic Kampuchea once again sought Beijing’s backing at the end of 1977. In September 1977, a senior delegation from Phnom Penh hurriedly headed to Beijing in an attempt to seek Chinese support against possible military retaliation from Hanoi. There is no evidence of any Cambodian official statement that clearly spelled out its alliance policy with China at that time. Nonetheless, the enthusiastic reception of DK leaders by the Chinese suggests Cambodia was perceived by the Chinese as an ally. The DK delegation was, according to Chang Pao-Min, made unusually welcome by the Chinese. More importantly, Beijing backed Phnom Penh’s efforts to tackle the threat from Hanoi when Chinese Premier Hua Guofeng declared that Beijing would “always be on Cambodian side” in its “just struggle against imperialism and hegemonism,” – Viet Nam apparently being the imperialist hegemon to which Hua referred.
III. Cambodia’s Contemporary Foreign Policy (1998-2017)
Hedging again became predominant in Cambodia’s foreign policy towards Viet Nam, especially, following the CPP’s full grip of the government in 1998. Cambodia’s hedging strategy throughout this period consisted of economic pragmatism, binding engagement, and soft-balancing. While economic pragmatism and binding engagement generally indicate this small state’s acts of deference towards its larger neighbour, soft-balancing demonstrates Cambodia’s attempt to stand up to Vietnamese power.
Economic pragmatism refers to a policy whereby a state, regardless of its size, makes efforts to maximise economic benefits from its direct trade and investment connections with a great power, regardless of any political conflicts between them. The increasing bilateral trade turnover and inflows of Viet Nam’s foreign direct investment (FDI) into Cambodia over the years serve as proof of Cambodia’s efforts to seek maximum economic benefits from its trade and investment links with Viet Nam. Two-way trade between the countries trended upward overall, despite occasional drops. Bilateral trade, according to the Cambodian Ministry of Economy and Finance, grew significantly, from US$130.7 million in 1998 to US$642.4 million in 2008, US$1.03 billion in 2011, US$1.12 billion in 2015 and US$1.64 billion in 2016.
As a smaller state, Cambodia has concurrently adopted the approach of so-called binding engagement with Viet Nam, utilising different levels of interaction between the two countries. Phnom Penh’s strategy is to increase interactions and communication with Viet Nam with the expectation that they will eventually contribute to binding its larger neighbour’s behaviour in bilateral agreements, in order to resolve differences or conflicts of interests in a peaceful manner. To achieve this, Cambodia has actively engaged with its larger neighbour through frequent exchanges of government-to-government and party-to-party visits with Vietnamese top leaders. Between 1998 and 2017, there were at least forty-three high-level visits to Viet Nam by Cambodian officials, compared to twenty-three visits by Viet Nam to Cambodia.
One should not underestimate this form of engagement, as it has helped to bind Cambodia’s larger neighbour to agreements that have ultimately contributed to peaceful settlement of disputes and the protection of Cambodian territorial sovereignty. For instance, during Viet Nam’s Prime Minister Dung’s visit to Cambodia in April 2011, the two sides concluded a memorandum of understanding (MoU) on the modification of some remaining areas of the land boundaries between the governments of Cambodia and Viet Nam. The conclusion of this MoU was crucial for Cambodia’s security, for it legally bound its larger neighbour to resolving the border problems in a peaceful manner. The conclusion of this historic document helped ease Cambodia’s traditional concern about Viet Nam’s gradual absorption of its land.
Along with limited bandwagoning, economic pragmatism, and binding engagement, Phnom Penh has simultaneously pursued a soft-balancing policy towards Hanoi. Cambodia’s soft balancing can be seen in its alignment policy with China, a state that has become ever more assertive in pressing its territorial claims against Viet Nam in the South China Sea since mid-2009.
An example of Cambodia’s soft-balancing was displayed during Defence Minister Tea Banh’s visit to Beijing in early July 2015, during which border tensions between Cambodia and Viet Nam flared up. During his meeting with the Vice Chairman of the Central Military Commission, Xu Qiliang, Tea Banh received an expression of support for Cambodia’s sovereignty from his Chinese counterpart. Tea Banh, in return, pledged to support China on the same issue. Although the term ‘sovereignty’ was vaguely defined, it can be concluded logically that Cambodia was bandwagoning with China in order to countervail Viet Nam. This is the first time a high-level Cambodian has officially supported China’s sovereignty claims without reservation.
The Kingdom’s current foreign policy is a break from the policy adopted by Cambodia in the preceding eras: 1970–1975 and 1975–1979. These periods were marked by soft and hard balancing strategies. The Khmer Republic (1970–1975) embraced hard balancing and soft balancing, whereas Democratic Kampuchea (1975–1979) adopted hard balancing exclusively in relations with Viet Nam.
Lon Nol openly received aid from Washington, reconciled with his domestic opponents as the Americans had advised, turned a blind eye to the US bombing of Cambodian territory, and demonstrated pliability to the US in battling DRVN troops. In terms of hard balancing, the Khmer Republic was not reluctant to wage war against DRVN forces and to use its military to murder and detain Vietnamese civilians inside the Kingdom.
Democratic Kampuchea adopted an exclusively hard balancing policy in relations with the reunified Viet Nam. Such a policy was evinced by Phnom Penh’s efforts to create a military alliance with Beijing, its enhancement of its military capability, and acts of aggression against Viet Nam. Democratic Kampuchea, on multiple occasions, sought Beijing’s military backing in order to counter Hanoi, and Beijing responded positively to Phnom Penh’s quest for an alliance. Further, the Khmer Rouge government upgraded its military capability to offset that of Hanoi by importing modern Chinese military hardware. More notably, Democratic Kampuchea proactively invaded Vietnamese territory, despite its inferior military power. One can say that the DK used war to deter any future Vietnamese invasion of Cambodia.
From 1998 onward, Cambodia has engaged in hedging against Viet Nam. While economic pragmatism and binding engagement were embraced in order to strengthen its relations with its larger neighbour, soft balancing was simultaneously used to deny the Vietnamese influence over the Kingdom. Economic pragmatism was evinced by Cambodia’s efforts to boost its trade and investment ties with Viet Nam. As for binding engagement in relations with Viet Nam, since 1998 Cambodia has promoted exchanges of senior government officials between the two countries in the hope of binding its neighbour to official agreements or otherwise obtaining positive responses from the latter on issues of concern to Cambodia. Simultaneously, Cambodia has sought to counter Vietnamese influence through soft balancing. This was seen in Phnom Penh’s intent to enhance military ties with Beijing. Through embracing multiple policy responses, Cambodia has been able to secure peaceful relations with Viet Nam, while concurrently ensuring its independence vis-à-vis the latter.