To What Extent was the 1979 Sino-Vietnamese Border War about Cambodia?

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The Sino-Vietnamese War of February to March 1979 is a period of conflict that is somewhat overlooked by considerable elements of Western memory and academic thought.  The conflict – despite lasting slightly less than a month – caused massive devastation across a North Vietnam already mauled by decades of war and resulted in the death or wounding of tens, if not hundreds of thousands of people.  However, these two bitter foes of the late 1970’s had earlier in the decade been supposedly ‘closer than lips and teeth’ (Chen. 1987. 9), to use an oft utilised diplomatic phrasing of the time.  What drove them apart?  Among several arguments put forward the idea that it was due to the December 1978 Vietnamese invasion and subsequent occupation of Pol Pot’s Cambodia has gained credence as the primary factor that caused the conflict.  However there were other forces at work – both particular to the region and further afield – that most certainly had an impact upon the two nation’s march to war, and discerning the extent to which the invasion of Cambodia was directly causative of the subsequent Sino-Vietnamese conflict is the purpose of this essay.  This will be done by studying various secondary source materials to gain a better understanding of the argument for the importance of Cambodia as well as of the other factors at play, and how these acted in concert to force the two nations from allies to enemies in a relatively short space of time.

It is sensible therefore to add some grounding to the argument that the Vietnamese invasion of Cambodia was the major cause for war between the People’s Republic of China (PRC) and the Socialist Republic of Vietnam (SRV).  There is a good case to be made.  Vietnam’s invasion of Cambodia was as a direct response to incessant and increased provocations on the border by Pol Pot’s regime.  Beginning on Christmas Day 1978, the battle hardened Vietnam People’s Army (VPA) quickly uprooted the loosely organised Khmer Rouge, installing its own government in Phnom Penh.  However –somewhat ironically considering Vietnam’s recent history – this conflict mutated into an insurgency that continued throughout the 1980’s.  Members of the PRC were quick to denounce the SRV’s actions.

Since coming to power in 1975 the Chinese had been rightly considered to be the ‘most trusted and powerful of friends’ (Chen. 1987. 31) of the Khmer Rouge, providing material and diplomatic assistance to that embattled and backward state.  This was largely due to an enduring and major Chinese strategic fear of a powerful neighbour on its southern flank as a serious secondary threat to the Russians in the north, and in the newly reconstituted Vietnam, like with the US before it, members of the Politburo in Beijing saw a potential realisation of this threat.  It thus sought a policy of a fragmented Indochina ‘in which Laos and Cambodia retained some autonomy vis-a-vis Hanoi’ (Lawson. 1984. 4).  The former had already drifted towards Vietnam, signing a ‘Laos-Vietnam Treaty of Friendship and Cooperation’ in September 1977 (Ross. 1988. 147) and now the massive and sustained VPA incursion into its neighbour was seen as a step too far.  This was the main reason given by the PRC as its justification for war and almost undeniably the most immediate cause.

However, to attribute the Sino-Vietnamese War in its entirety to the Cambodian issue is fundamentally misguided.  As Anne Gilks persuasively argues, the invasion – rather than being a base cause of conflict for these two countries – merely ‘reinforced the tensions and pressures playing upon the fragile Sino-Vietnamese relationship’ (Gilks. 1992. 169).  To put it another way, it is arguable that had the SRV and PRC been on better terms then Beijing would have been much less concerned about a Vietnamese predominance of power on its southern flank.  It was precisely because this hitherto ally was now seen as a threat rather than a friend that the Cambodian incursion was seen as a justification for war.  Thus it can be argued that whilst the Vietnamese invasion of Cambodia was a major short term cause for the ensuing Sino-Vietnamese War, a more substantial and in-depth analysis of the other structural and underlying deficiencies in the wider Sino-Vietnamese relationship is a prescient prerequisite to gaining the best understanding of their subsequent hostilities.

Foremost amongst the factors affecting the Sino-Vietnamese relationship was the wider schism in the global communist movement between its two great powers of China and the USSR.  This Sino-Soviet split – beginning in the early 1960’s and increasing in importance throughout that decade – had a massive effect upon communism itself and the wider Cold War.  The split was not amicable, and almost led to full-scale war between the two nations.  This meant that for emergent Socialist countries, there was now a choice that was not only available but had to be made – to tilt towards either the Soviets or the Chinese for aid and favour.

This is exactly what happened with Vietnam following reunification.  Facing a stark choice between their oft threatening northern neighbour and the monolithic Soviet Empire, Hanoi opted for the latter for the political and material value they could add as compared to the PRC; for example, it is estimated that ‘the USSR…was supplying as estimated $500 million annually in economic aid’ (Gilks. 1992. 183) to Vietnam in the mid 1970’s.  As Westad argues, ‘the Vietnamese challenges…in the Cold War would not have been possible for the Sino-Soviet split of the early 1960’s’ (Westad. 2005. 158) as Vietnam’s own international clout could do little to affect Chinese global strategy.  Furthermore, as the Sino-Soviet split became increasingly entrenched in international politics, China began to feel arguably just as threatened (if not more so) by the intrusive ‘hegemon’ that was the USSR as it was by the USA.  Subsequently those fears led to a view that states that followed the Soviet path were inherently agents of Moscow, and thus threatening to the Chinese brand of communism, and the Vietnamese – who gradually became seen as the ‘Cuba of the East’ (Ross. 1988.173) were chief among them.   Therefore it can be reasonably be argued that with regards to the Sino-Vietnamese relationship ‘the downward momentum…stemmed largely from the relationship of Vietnam and the USSR’ (Gilks, 1992. 169).  Consequently we can see a better justification for the Chinese objection to the Vietnamese invasion of Cambodia, as this would have had a ‘dramatic effect on the balance of power in Indochina’ (Hood.  1992. 59) which in itself may not have been seen as a threat but due to ‘Vietnam’s increasing dependence upon the USSR’ that made an ‘Indochina under Vietnamese domination unacceptable’ (Lawson. 1984. 4).  This adds both some depth and a distinct alternative to the original assessment of Cambodia as the primary impetus for war.  It was not merely a Vietnamese domination of Cambodia that Beijing feared, but was rather a concern that an increasingly aggressive Vietnam, acting as an arbiter of a hostile Moscow’s foreign policy could gradually transform the strategically vital Indochinese peninsula into a serious southern flank threat to the PRC.   Thus this conclusion evidences the value of King C. Chen’s suggestion that ‘had there been no Soviet-Vietnamese alliance, the war between China and Vietnam might not have been fought’ (Chen.  1987. 28).

Another aspect of the relationship that caused geo-strategic tension were the territorial disputes that affected both nations.  These long running disagreements largely concerned three geographically distinct areas: ‘the 797-mile borderline, the Gulf of Tonkin and the Spratly islands’ (Chen. 1987. 39).  Largely apolitical in nature, they concerned the boundaries, both at land and sea, that the SRV (as a new nation) laid claim to.

These issues had existed before the end of the war in 1975 but their antagonistic potential had been subsumed for the greater cause of combating the American forces in the region.  Now these disputes were frequently used by both sides as evidence of and justification for increased aggression between them.  To use a statistical example, by Vietnamese accounts the number of border incidences between the two nations in 1974 stood at 117.  By 1978 however, this figure had increased to 2175 (Chen. 1987. 50).  Considering the Vietnamese invasion of Cambodia came at the very end of that year, attributing this increased tension purely or even majorly towards that event does not adequately justify all that came before it.

However, equally it is difficult to effectively utilise the territorial disputes between the two nations as a serious cause for the specific 1979 war itself.  It is undeniable that these issues were a significant source of tension; however, to argue that they were anything more than a reactive source of tension is difficult to substantiate.  It is noted by several scholars that ‘incidents along the border continued to increase as tension mounted’ (Gilks.  1992. 227).  This crucial distinction – ‘as tension mounted’ – rightly implies that these underlying issues were pre-existent but eminently acceptable if there was no other source of tension separate from the border disputes themselves.  Indeed, as Chen argues, ‘territorial disputes only began to occur after the Sino Vietnamese relationship had turned sour’ (Chen. 1987. 39).  Thus with regard to the territorial disputes between these two nations we can legitimately consider that ‘this aspect of the dispute was overshadowed by other elements of the conflict’ (Hood. 1992. 123), and although being a very public and frequent cause of tension between the two countries they were predominantly more symptomatic rather than diagnostic with the relation to the strains experienced in Sino-Vietnamese relations in the run up to their eventual war.

There were also several non-geo strategic areas of friction between the PRC and SRV that can now be looked at.  Primary among these was the issue of the large minority of ethnic Chinese living in Vietnam.  Known as the Hoa, this group was a substantial minority in Vietnam for much of its history, with a seemingly uncanny ability to dominate the economy that many ethnic Vietnamese had long resented (Hood. 1992. 140).  From the middle of the 1970’s onwards Hanoi began to systematically limit and persecute the Chinese resident in Vietnam through both law and neglect in a conscious strategy to subvert their influence into a greater Vietnamese society.  Despite this reason being seemingly of little impact in relation to the pragmatic realism that Beijing is oft known for, the PRC’s reaction was not negligible.  It is in fact argued that ‘the first serious signs of strain between Vietnam and China came…when Beijing expressed concern over the mistreatment of ethnic Chinese living in Vietnam’ (Hood. 1992. 135).  Throughout 1977 and 1978, as Hanoi’s political attacks on the Hoa got ever more draconian Beijing got increasingly agitated, repeatedly warning Hanoi ‘that its ethnic Chinese policy might elicit a sharp response’ (Ross. 1988. 155).  Hanoi was not deterred and continued to exclude the Hoa to the margins of Vietnamese society, leading to the argument that it was this policy that served to ‘break the final strands of its cooperative relationship with Vietnam’ (Gilks. 1992. 192).

However, as with all the other factors outlined in this essay, it is impossible to view this argument in isolation from its context.  It is not suggested or implied in any of the source material that this was seen or meant to be received as a purely isolated incident evidencing some new-found ethnic intolerance on the part of Hanoi.  Beijing quickly got the impression that this policy and its seemingly rapid implementation ‘evidenced Hanoi’s alignment with the USSR’ (Ross. 1988. 198) as Hanoi felt it had to place itself firmly in the Soviet camp by ‘counterbalancing any possible pressure from China’(Chen. 1987. 66) it sought to curtail the independence and (informal) power of the Hoa community in Vietnam.  Thus the issue was not just a human one to the PRC Politburo but a realist one, as here was further evidence of the increasingly antagonistic approach that Hanoi was taking in comparison to Beijing, and another instance of ‘Soviet meddling’ (Ross. 1988. 165) in the Indochinese peninsula.  As a final caveat that may help show the rational calculation under Beijing’s seemingly ‘emotional response’ (Chen. 1987. 68) was the issue of the ethnic Chinese in Cambodia.  Among the estimated two million killed during the Khmer Rouge’s short time in power an estimated ‘200,000 ethnic Chinese died’ (Ross. 1988. 186) – showing that Beijing could and did ignore the issue of its ‘ethnic brethren’ when raison d’état demanded.  Thus the only viable conclusion available is that the strong Chinese reaction to the treatment of the Sino-Vietnamese in Vietnam was a combination of the very public mistreatment of the Hoa with a growing PRC belief that this was further indication Vietnam was increasingly acting in concert with the USSR to undermine vital strategic interests of the PRC.

A final area to be looked at concerns both the ancient and modern historical legacies and themes surrounding the Sino-Vietnamese relationship.  Whilst this area is perhaps a more permissive and pervasive factor than what has been discussed up to now; it is nevertheless relevant as, like Eugene Lawson states: ‘Sino-Vietnamese relations were shaped in the crucible of history’ (Lawson. 1984. 1).

Consequently, it is chronologically sensible to begin with the extant and enduring relationship that the historic Chinese and Vietnamese peoples created in the centuries before the modern nations themselves arose.  Long known to itself and others as ‘the Middle Kingdom’ the Chinese nation in its various entities had long sought to secure its sovereignty by dominating its peripheries – and Vietnam was no exception.  Through invasion, subversion and diplomacy ‘China … pervasively and continuously influenced Vietnam for 2000 years’ (Lawson. 1984. 17).  Indeed, it has even been argued that ‘the North Vietnam government…inherited the ancient ambivalent view towards its Northern neighbour’ (Ibid.).  Whilst this view may seem to a point transient and irrelevant, its veracity can be seen in the culture of conflict that arose in the 1970’s.  For example, with regards to the territorial disagreements, a major sticking point on the part of Hanoi was a fear that ‘once territory agreement had been established the PRC would put forward even larger demands’ (Ross. 1988. 153) – a sure indication that Hanoi was exercising, at least in part, its inherent mistrust of Beijing.

The impact of the decades running up to the descent into conflict of the 1970’s is important too.  Despite being relatively firm allies throughout the US intervention, Hanoi on more than one occasion charged China with attempting to ‘prevent Hanoi from fully liberating the South’ (Chen. 1987. 21) – which was in large part true, and evidence of China’s aforementioned policy to keep Indochina fragmented politically.  On Beijing’s side, many in the Politburo felt that ‘as US influence faded the Soviet Union moved to fill the vacuum’ (Lawson. 1984. 32) which, as well as showing its concerns about the incipient threat of the USSR implicitly acknowledges the idea that it, rather than any competitor, is the sole master of its own borders and the nations directly beyond them.  Accordingly this analysis of the (both ancient and modern) historical culture of mistrust between the two nations gives far greater substance to the innate atmosphere of mistrust that pervaded Sino-Vietnamese relations, providing a fertile breeding ground for the disputes that were to mark their road to war.

Consequently, in conclusion to the issues discussed above, it can be seen that the motives for war surrounding the commencement of the month-long Sino-Vietnamese conflict of early 1979 are much more interlinked and multi-faceted than one may suppose.    It is correct that the PRC saw a fragmented Indochinese peninsula as key to their strategic security – and the newly unified and aggressive Vietnam was seen as a major threat to that.

However to understand why Vietnam – a similarly avowedly Communist state – was seen as a threat a deeper analysis is required.  In essence, the Sino-Vietnamese relationship is a clear and stark example of and warning for the dangers an unchecked security dilemma spiralling upwards in intensity can pose to international stability.  Once relations began to sour each reaction on the part of one came to seen as hostile pro-action by the other, necessitating a sharp response that perpetuated the cycle.  This raised the tension to a level where the only remedy lay in war.  A historical Vietnamese mistrust of the ‘Middle Kingdom’ and the power vacuum in Indochina following the US withdrawal set the scene for conflict.  The expansion of Soviet interests there meant that, due to the significantly hostile Sino-Soviet relationship China felt threatened by Vietnam as an arbiter of Moscow’s foreign policy.  This hostility drove Vietnam further towards the USSR and away from China, resulting in the persecution and expulsion of overseas Chinese in an attempt to neutralise some of a growingly hostile Beijing’s influence.  This was viewed by the PRC as an emotional and provocative move that only served to entrench their perception of Vietnam as a hostile Soviet client.

This climate of distrust and dislike existed separately from the Cambodia-Vietnam-China triangle; however Vietnamese aggression there was seen by Beijing as the final straw, and was directly resultant in the conflict that began three months later.  It would be wrong to fully discredit the idea that the Vietnamese invasion of Cambodia was a major cause of war; however equally it would be inaccurate to portray it as the stand-alone pivotal factor that necessitated conflict; a broad Constructivist picture of the entire condition of Sino-Vietnamese relations is a prerequisite to understanding their gradual descent into war.


Chen, King C. (1987) China’s War with Vietnam 1979
Gilks, Annie (1992) The Breakdown of the Sino-Vietnamese Alliance
Hood, Steven J. (1992) Dragons Entangled: Indochina and the China-Vietnam War
Lawson, Eugene (1984) The Sino-Vietnamese Conflict
Ross, Robert S. (1988)The Indochina Tangle: China’s Vietnam Policy, 1975-79
Westad, Odd Arne (2005) The Global Cold War: Third World Interventions and the Making of our Times 

Written by: Harry Booty
Written at: Kings College London
Written for: Dr Peter Busch
Date written: 29/03/2012

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