This article offers new insights into a still poorly understood issue – namely the dynamics shaping the Sino-Vietnamese territorial disputes and the mass exodus of ethnic Chinese from northern Vietnam between 1974 and 1978. Relying on previously unavailable Vietnamese internal government documents in conjunction with existing scholarly works based on Chinese sources, this study challenges dominant narratives, which attribute the exodus to the collapse of Sino-Vietnamese relations, by providing a far more detailed and comprehensive account.Footnote ¹ I argue that two variant forms of Vietnamese nationalism – one emphasizing “forced assimilation” as a demonstration of loyalty, and the other the need to protect the “fatherland” (tổ quốc) from further territorial losses to Chinese expansionism – reinforced one another and catalyzed the flight of Chinese residents and technical experts in 1977–1978. Specifically, during the period 1974–1978, the two variant forms of state-sponsored nationalism enacted in sequence against the perceived threat of Chinese territorial expansion created a climate of fear in Vietnam which exacerbated the mistreatment of these Chinese residents and experts, which in turn provoked increasingly bellicose responses from China. Pro-Soviet Vietnamese rhetoric and chauvinistic actions in Cambodia and Laos in the context of growing competition between Hanoi and Beijing over Indochina after 1968 prompted Chinese concerns regarding Vietnamese expansionism there as well.Footnote ² Over time, this created a negative feedback loop where “tit-for-tat” land grabbing at the local level quickly undermined any possibility of a negotiated agreement on the disputed territory and rapidly escalated the Sino-Vietnamese border conflict, with spiraling negative effects on other issues. This gave Beijing cause to cut off all Chinese aid to Vietnam in early 1978. The result was the brief but extremely bloody border conflict in February 1979. China's incursion was a massive military operation, its largest since the PLA intervention in the Korean War, involving at least 450,000 troops; the 80,000 troops that China actually committed were met by some 75,000–100,000 Vietnamese militia and troops, of which 50,000 were regular combat forces.Footnote ³ Casualties were high, and roughly comparable on both sides: an estimated 25,000–28,000 Chinese dead and 37,000 wounded and 20,000 Vietnamese dead and 35,000–45,000 wounded.Footnote ⁴

In Hanoi's view, Beijing's opportunistic use of force in January 1974 to consolidate its control over the Paracel islands was clear evidence of territorial expansionism, and this provided a rationale for Vietnamese leaders to articulate anti-China nationalism. The Sino-Vietnamese tit-for-tat struggle in the ensuing years produced negative spillover effects in three related areas. First, as Chinese territorial expansion continued along its southern boundaries, Hanoi became increasingly concerned about the loyalty of Chinese residents in Vietnam toward China, especially those living in the northern part of the country. As a result, Hanoi intensified its policy of nationalizing Chinese residents through forced assimilation and demands for public expressions of loyalty to the Vietnamese state, and through the dissemination of anti-China propaganda. Such policies encouraged mistreatment of Chinese residents by local Vietnamese authorities, and further inflamed China's animosity toward Vietnam, particularly among top Chinese leaders including Deng Xiaoping, who was keen on taking punitive action against Vietnam. Second, as Beijing expressed grave concern for the plight of ethnic Chinese residents in Vietnam, this raised expectations among the minority Chinese community in Vietnam that it would be either incorporated into greater China or be physically protected by the Chinese government. Having developed such expectations, Chinese residents resisted direct attempts by the Vietnamese government to integrate them more firmly under the state's control through forced assimilation policies. Finally, the mass exodus of Chinese residents from Vietnam, estimated at 450,000, of whom more than 160,000 (a figure raised to some 240,000 according to Beijing's claim in July 1979) were forced from northern Vietnam across the Chinese border, gave the Chinese government cause to escalate economic sanctions against Vietnam in 1977–1978 and the punitive war against Vietnam in February 1979.Footnote ⁵

This article is divided into three sections. The first discusses Sino-Vietnamese cultural-historical factors and the post-independence political discourses that shaped Sino-Vietnamese solidarity in the context of their common struggle against French colonialism and U.S. imperialism from 1950 to 1973. This section highlights Hanoi's growing resentment towards Beijing's domination and territorial boundary delineation between the two wartime allies, which intensified the emotional foundation of Vietnam's anti-China nationalism. The second section traces the evolution of the Sino-Vietnamese territorial dispute from its initial triggering to the escalation phase of the conflict (1974–1976). The third section examines the consequences of failed bilateral negotiations and the impact of escalated tensions between the two nations (from 1977 to early 1978), which laid the foundation for the Third Indochina War.

THE ILLUSION OF THE “BROTHERS PLUS COMRADES” DISCOURSE, 1950–1973

The history of Sino-Vietnamese interaction is a long one. The Vietnamese collective memory of Chinese domination over two millennia contained an important reservoir of narratives of heroism against Chinese hegemony, which Vietnamese nationalists drew upon to mobilize the people against future Chinese aggression.Footnote ⁶ While the main source of Vietnam's capability to repel repeated Chinese invasions, or to make Chinese occupation of Vietnam untenable, may have been a sense of heroic nationalism, at the same time there existed conscious emulation of Chinese political and military institutions, which not only proved instrumental in countering the Chinese threat, but also gratified Chinese emperors supremely confident of their own cultural superiority.Footnote ⁷ As William Duiker correctly observed, “As for the Vietnamese, their attitude toward China was a unique blend of respect, and truculence, combining a pragmatic acceptance of Chinese power and influence with a dogged defense of Vietnamese independence and distinctiveness.”Footnote ⁸ The overwhelming emphasis of official Vietnamese history is on national resistance against foreign invaders, almost always China. This historical legacy remains a powerful force affecting contemporary Sino-Vietnamese relations.

The period 1950–1965 saw the closest cooperation between the two neighboring countries. During this period, leaders of the Vietnamese Workers’ Party (VWP) and the Chinese Communist Party (CCP) articulated a common discourse of “brothers plus comrades” Sino-Vietnamese intimacy.Footnote ⁹ Both sides negated the negativity of the past – that is, the history of Chinese aggression on and subjugation of Vietnam for two millennia before the French colonialism of the nineteenth century. Instead, they emphasized the People's Republic of China as a new revolutionary state of Chinese proletarian peasants and workers who had for centuries fought relentlessly against oppression from Chinese feudalism and European colonialism.Footnote ¹⁰ For instance, on 18 October 1956, Nhan Dan, the VWP Newspaper, published an editorial to welcome Premier Zhou Enlai's visit to the DRV by starting with this observation: “For a few thousand years, our two peoples fought against the feudal rulers [referring to both the Chinese and Vietnamese feudalists], and most recently, we fought against colonialism [by recalling the memory of the Chinese “Black Flag” popular movement that crossed the Sino-Vietnamese border to fight French troops alongside the Vietnamese people in Northern Vietnam.]”Footnote ¹¹ Zhou Enlai then reciprocated by paying homage to the Hai Bà Trưng (“Two Sisters”) who rose up against Chinese imperialism in AD 43 to denounce Chinese dynasties’ chauvinism toward Vietnam in the past.Footnote ¹² In reality, this “brothers plus comrades” discourse was shrouded in strategic calculations on both sides. As Qiang Zhai put it, “The Sino-DRV alliance was one of mutual needs. While Hanoi wanted China's aid in its struggle against the French and the U.S., Beijing also needed the DRV's support for its foreign policy goals.”Footnote ¹³ For Hanoi, China's economic and military support for its war against the French return to Indochina was indispensable, while the Soviet Union was indifferent toward the Vietnamese cause.Footnote ¹⁴ Yet, Hanoi maintained a working relationship with Moscow and secretly expressed a desire for Soviet aid after the French departure in 1955.Footnote ¹⁵ For Beijing, North Vietnam, like North Korea, was a strategic buffer zone to defend China's southern flank against threats from unfriendly Western powers and served to validate the PRC's identity as a champion of national liberation struggles against colonialism and imperialism.Footnote ¹⁶

During the early 1950s, the VWP was swept up by the brief illusion that the “brothers plus comrades” relationship between the two communist parties would usher Sino-Vietnamese relations into a new historical chapter of an equal alliance. However, although both the CCP and VWP saw the need to articulate a newly shared history of victimhood under the yoke of past Chinese dynasties and the common cause of resisting French colonialism, they fundamentally differed with regards to the nature of the newly forged alliance. In public, Chinese leaders repeatedly emphasized the rhetoric of “equality and mutual respect for independence” as a core principle of their new relationship. In practice, however, their attitude towards the Vietnamese resembled one of a teacher–student relationship.Footnote ¹⁷ In the memory of Vietnamese leaders, the Chinese impulse to betray the Vietnamese revolution could be traced back to Beijing's advice during the 1954 Geneva Conference which culminated in the division of Vietnam until 1975.Footnote ¹⁸ Yet, such resentment did not develop into open hostility because the Vietnamese attached the highest priority to Chinese assistance to liberate South Vietnam. Indicative of this, in response to the Republic of South Vietnam (RSV)'s forced assimilation policy of Chinese residents in 1955, Hanoi verbally agreed to the principle of voluntary assimilation of Chinese residents; in 1957, North Vietnam and China signed a bilateral agreement in which Hanoi pledged not to resort to forced assimilation of Chinese residents the way the RSV had in South Vietnam.Footnote ¹⁹

In early 1958, as Hanoi pursued a new phase of “armed struggle” to liberate South Vietnam, it needed increased Chinese economic and military aid. In this context, Beijing turned an unrelated crisis into an opportunity to exert its territorial interest in the South China Sea at a juncture when Hanoi was weak and heavily dependent on China's help. In late August 1958, Mao riskily decided to shell the island of Quemoy, provoking the second Taiwan Strait Crisis that escalated into a military showdown with the United States. On 4 September 1958, Beijing declared that the territory of the PRC “includes the Chinese mainland, its coastal islands, Taiwan, and its surrounding islands including the Penghu Islands, the Dongsha Islands, the Xisha (Paracel) Islands, the Zhongsha Islands, the Nansha (Spratly) Islands and all other coastal islands by the high seas.”Footnote ²⁰ On 14 September 1958, Vietnamese Prime Minister Pham Van Dong sent to Chinese Premier Zhou Enlai a letter which “recognizes and supports Beijing's September 4 declaration.”Footnote ²¹ In reality, the leadership of the DRV had no legal right to cede any territory south of the Seventeenth Parallel to China because it was part of the RSV's territorial sovereignty. Later, on 10 June 1977, when challenged by Chinese Vice-Premier Li Xiannian, Pham Van Dong rationalized Vietnam's earlier position by arguing that it was a “matter of war necessity” to support China's claims during the war because of the need to “place resistance to U.S. imperialism above everything else.”Footnote ²² In rebuttal, Li Xiannian replied: “There was no war going on in Vietnam when on September 14, 1958 Premier Pham Van Dong … acknowledged in his note to Premier Zhou Enlai that the Xisha and Nansha Islands are Chinese territory.”Footnote ²³

In late 1964 to early 1965, faced with the prospect of a U.S. invasion of North Vietnam, Hanoi's leaders were deeply concerned about Beijing's hesitation to go to war with the U.S. to defend their nation. Although Mao Zedong had formulated a militant approach towards the U.S. since the summer of 1962, and assured Hanoi's leaders of China's general commitment to defend North Vietnam in the event of a U.S. attack, Hanoi suspected that Mao was attempting to avoid direct military confrontation with the United States. Even after the Johnson administration made the decision in February and March 1965 to launch a sustained bombing campaign against North Vietnam (known as Operation Rolling Thunder), Mao consistently counseled caution.Footnote ²⁴ On 9 May 1965, Hanoi undertook another initiative to declare that “the Paracel and Spratly Islands belong to China.”Footnote ²⁵ Pham Van Dong again raised the necessity and priority of resisting U.S. imperialism because the islands were at that time under the control of U.S. and South Vietnamese armed forces.Footnote ²⁶ In hindsight, Hanoi's leaders were compelled to recognize Beijing's claim publicly because of the necessity of enlisting China's all-out support for the greater cause of armed struggle against U.S.-backed South Vietnam, and consequently could not articulate their own interests in opposition to China. In private, they greatly resented China's opportunistic territorial assertion at a time when Vietnam was heavily dependent on Chinese assistance.

Yet, it was the spillover effects of Mao Zedong's Cultural Revolution during its height in 1966–1968 on North Vietnam that consequently brought the mutual distrust poorly concealed during the fifteen-year period of close Sino-Vietnamese cooperation back to the surface, and caused the Vietnamese to fear Chinese chauvinism once again.Footnote ²⁷ During the height of the Cultural Revolution, the discourse of “brothers plus comrades” Sino-Vietnamese solidarity was put to a real test for the first time, and more clearly revealed both sides’ strategic interests poorly concealed behind a very thin veil of historical and ideological solidarity. As the historian Chen Jian best puts it, “What Beijing intended to create was a modern version of the relationship between the Central Kingdom and its subordinate neighbors. This practice effectively reminded the Vietnamese of their problematic past with the Chinese … .”Footnote ²⁸ Chen Jian's observation resonates with the official view of the Vietnamese government at that time. Much later, on 10 June 1977, a year after the Cultural Revolution's end, Pham Van Dong told Chinese Vice-Premier Li Xiannian and other senior Chinese officials from the Ministry of Foreign Affairs that “for many years, especially during the Cultural Revolution, many Chinese comrades have been publicly very rude to us. They called us ‘revisionists’ because we accepted Soviet aid, and even called us ‘ungrateful.’ Using this kind of language, Chinese comrades harbored an unfriendly attitude towards us. Such attitudes exist in Hanoi, Beijing, and other places. Such attitudes have broken our hearts.”Footnote ²⁹

At the height of the Cultural Revolution, the Maoist radical faction took control of the Chinese Embassy in Hanoi. They rallied Chinese residents in northern Vietnam to support Mao's Cultural Revolution, promoted the Cultural Revolution ideology of “class struggle,” instigated anti-Soviet revisionism campaigns, and even openly denounced Vietnamese leaders as “revisionists” for accepting Soviet assistance.Footnote ³⁰ Chinese residents created disturbances by holding demonstrations against Soviet revisionism and openly conducting other pro-Maoist rallies in Hanoi. To the Vietnamese, these Chinese residents were “reactionary Chinese nationals.”Footnote ³¹ As Han Xiaorong observed, “If the Chinese in North Vietnam were already on their way to becoming Vietnamese citizens before the Cultural Revolution, then the Cultural Revolution caused a reversal of this trend.”Footnote ³² It proved to Vietnamese leaders that these Chinese residents remained loyal to their “motherland China” by blood.

In response to the spillover of the Cultural Revolution, Hanoi saw the need to invoke the familiar “the threat of aggression from the North” discourse to remind the Vietnamese public of Chinese chauvinism, even while they accepted Beijing's dispatch of some 320,000 Chinese “volunteers” to assist the North Vietnamese against the United States from 1966 to 1969.Footnote ³³ This in turn profoundly irritated Beijing's leaders because “Vietnam's use of the past to imply the present” betrayed the spirit, and would undermine the emotional foundation, of the Sino-Vietnamese “brothers plus comrades” solidarity. Since 1950, Beijing had clearly and consistently condemned the historical aggression against Vietnam. In 1956 and again in 1970, Premier Zhou Enlai even paid homage to the Hai Bà Trưng (Two Sisters) Temple in Hanoi to pay respect to the two sisters who had risen up to resist feudal Chinese aggression against Vietnam.Footnote ³⁴

* * *

In summary, a close examination of Sino-Vietnamese relations during the period of close cooperation from 1950 to 1965, and during the height of China's Cultural Revolution from 1966 to 1968, reveals that Sino-Vietnamese solidarity was far from both sides’ rosy portrayal of a “brothers plus comrades” relationship, yet it remained calm through all the turbulence because maintaining the image of Sino-Vietnamese cooperation served the strategic interests of both sides and preserved solidarity against common enemies. Hidden beneath the surface of the “brothers plus comrades” relationship was Hanoi's suppressed resentment at Beijing's willingness to change its politics without regard to Vietnamese interests and growing fear of resurgent Chinese chauvinism in the form of an outdated Chinese “tributary system” over Vietnam. Although Vietnamese leaders acknowledged the importance of Chinese assistance to North Vietnam, they resented the fact that Chinese leaders did not shy away from imposing their will on North Vietnam when the latter was weak and heavily dependent on China's assistance. As a tactical response, Hanoi's leaders took initiatives to display tactical deference to China by declaring its recognition of Beijing's territorial claim over the Spratly and Paracel Islands, while they were not in a position to articulate their territorial interests in opposition to Beijing. Vietnam's repeated recognition of China's territorial claims in 1956, 1958, and 1965 was made with the ulterior motive of “compliance in face and betrayal in mind.” In their thinking, enlisting a greater commitment of aid from China and deeper engagement in military confrontation with the U.S. during this fateful decade from 1956 to 1965 was accorded the highest priority. When the Vietnamese fear of losing the war declined and the Soviets were eager to replace the Chinese as the main provider of economic and military assistance in 1974, Hanoi actively challenged Chinese territorial expansion, bringing the Sino-Vietnamese territorial dispute back to the surface. The land border between China and Vietnam became an issue of dispute because of shifts in position of border demarcations that had been made since 1955, and both sides accused each other of changing the status quo. The land border dispute turned into border clashes from 1974 onwards.Footnote ³⁵

HANOI'S RESPONSES TO CHINESE TERRITORIAL EXPANSION, 1974–1976

As Hanoi's military victory came into sight and the time-horizon of national unification was shortened, Beijing and Hanoi hastened to grasp whatever they could from the disputed land and maritime territory as potential leverage to turn the anticipated negotiations in their respective favor. Beijing's opportunistic use of military force to capture a number of major Paracel islands from the retreating RSV forces in January 1974 consequently sparked Hanoi's fear of further Chinese territorial expansion at the expense of a weaker Vietnam after the war, bringing the long-suppressed territorial boundary dispute between the two nations back to the surface. In Beijing's view, China's unilateral takeover of the Paracel islands in January 1974 from South Vietnamese control was legitimate because Hanoi had repeatedly recognized China's claims in 1956, 1958, and 1965, most importantly through Pham Van Dong's note of the DRV's acceptance of China's sovereignty claims on 14 September 1958.Footnote ³⁶ In reality, the primary motives of both Beijing and Hanoi were security and economic interests. The scholarly consensus is that by 1973 Chinese leaders were increasingly concerned about Hanoi's tilt toward Moscow and the consequent Soviet use of the islands as a military base to threaten China, and that the territorial disputes became acute because of the prospects for offshore oil around the islands.Footnote ³⁷ Similarly, Hanoi's change of mind about its past recognition of China's claims was largely motivated by the economic and security interest of gaining exclusive control of resources in the area and defending Vietnam's long S-shaped coast against invasion.Footnote ³⁸ In November 1973, Hanoi proposed talks on delineation of the boundary in the Gulf of Tonkin, on the grounds that the boundary of the two countries in the Gulf had never been clarified because Vietnam had been constantly at war. That aroused Chinese leaders’ concern that Hanoi had changed its mind about its war-time recognition of Chinese claims in the South China Sea.Footnote ³⁹

As it turned out, Hanoi's later responses confirmed Beijing's suspicions. Immediately after Beijing's January 1974 military campaign, Hanoi expressed a mild protest against the Chinese occupation of the Paracel islands by reminding Beijing that “the countries involved should settle such disputes through negotiation and in a spirit of equality, mutual respect, and good-neighborliness.”Footnote ⁴⁰ Nonetheless, as China consolidated its control over the Paracel islands, Hanoi moved quickly to preempt Chinese seizure of the Spratly islands. On 11 April 1975, three weeks before the capture of Saigon, the North Vietnamese navy attacked and occupied six of the islands previously held by South Vietnamese forces and immediately asserted its territorial claim over the Spratly Islands.Footnote ⁴¹ Throughout the second half of 1975, Hanoi and Beijing were engaged in a divisive exchange of anti-irredentist claims on the islands and the spinning of media campaigns to rally nationalistic fervor at home.Footnote ⁴² This tit-for-tat territorial contest between Hanoi and Beijing put the two war-time “brothers plus comrades” on a collision course, which in turn caused Chinese leaders to view Vietnamese leaders as “ungrateful and treacherous.”

Simultaneously, the land border dispute emerged into hotly contested territory and a slowly but steadily militarized zone between the two nations between 1974 and 1976. Starting in 1974, armed clashes occurred along the Sino-Vietnamese land border. Both sides accused one another of provoking the border skirmishes.Footnote ⁴³ On 18 March 1975, Beijing proposed that the two countries negotiate to settle the land border issue, but Hanoi preferred to delay such negotiations until after its liberation of South Vietnam, and allowed local authorities to resolve the disputes. Beijing later charged that “Hanoi intentionally delayed to allow local Vietnamese authorities to change the land boundary status quo.”Footnote ⁴⁴ Apparently, Beijing's motive, as Qiang Zhai pointed out, was to reach a settlement before the end of the war, while North Vietnam was still at a disadvantage.Footnote ⁴⁵ In the ensuing years, each side accused the other of betraying the 1955 principles of maintaining the territorial status quo. Mirroring the Chinese perspective of Vietnam's lack of good faith in resolving the territorial dispute, the head of the Vietnamese border negotiation delegation Phan Hien noted that over the course of the six months from October 1977 to March 1978, the Chinese had dragged their feet on border negotiations when the Vietnamese side did not make the concessions they wanted, and raised new issues outside the negotiation agenda, including “the issue of the Paracel and Spratly islands, the Vietnamese harassment of the Chinese along the border, and the flight of Chinese residents to China.”Footnote ⁴⁶ On the ground, the escalating territorial dispute along the boundary between the two nations turned the people on both sides of the border from brotherly comrades into bitter adversaries, and a once peaceful and open border into an increasingly militarized and closed border in a short span of just a few years. According to a Chinese record published by the People's Daily on 27 February 1979, the number of Sino-Vietnamese border provocations rapidly increased from 121 in 1974 to 1,108 in 1978 with a slight dip – dropping from 986 in 1976 to 752 in 1977, as Hanoi and Beijing tried to patch up their relations.Footnote ⁴⁷

FAILED BORDER NEGOTIATIONS, OCTOBER 1977 TO MARCH 1978

Lying at the core of the Sino-Vietnamese land border conflict after 1975 was Hanoi's refusal to accept the land boundary status quo on the basis of the Franco-Qing Treaties of 1887, which put Vietnam in a disadvantageous position. Worse, Beijing refused to negotiate with Hanoi on the issue of the Paracel and Spratly islands because Hanoi had ruled out the validity of its previous recognition of the PRC's claim over the islands, particularly Pham Van Dong's letter to Premier Zhou Enlai on 14 September 1958. Hence, there was no mutually agreed framework between the two governments. On 29 September 1975, in his meeting with Le Duan, Deng Xiaoping proposed a bilateral negotiation to solve the land border dispute once and for all, but Hanoi wanted to negotiate both land and water boundaries all at once.Footnote ⁹⁰ However, Beijing firmly disagreed with Hanoi's proposal and maintained that the bilateral talks would have to delay until Hanoi accepted Beijing's condition of negotiating the land border first. Beijing insisted that any land border negotiation would have to begin with the principle of the Franco-Qing Treaties of 1887, which the VWP and CCP agreed to in 1955, and that the status quo over the disputed territory would have to be observed in order to maintain friendship and economic relations along the Sino-Vietnamese border.Footnote ⁹¹ From 1975 to mid-1977, each side accused the other side of being unconstructive and unwilling to solve the issue through diplomatic means. After a long delay, Vietnam agreed to negotiate the land border with China in October 1977. As it turned out, however, both sides had allowed their local authorities to take opportunistic measures to gain every inch of the disputed territory from the other side, which produced a cycle of tit-for-tat land grabbing during the second half of 1977. On the Vietnamese side of the border, the measures resulted in the Vietnamese local authorities’ increased mistreatment of Chinese residents and rapid flow of Chinese refugees into adjacent provinces, mainly Yunnan and Guangxi in southern China. By mid-1978, nearly 200,000 ethnic Chinese refugees from North Vietnam had crossed the border into China.

Beijing leveled a consistent accusation that the Vietnamese side intended to use the language of negotiations to buy time to allow the local authorities and border defense forces to grab as much land as they possibly could in the disputed territory, as well as to collect as many cases of the Chinese side's violations as possible before coming to the negotiating table. Each side then launched accusations that the other side was violating the principle of maintaining the status quo, when in reality both sides were violating it. In his conversation with Pham Van Dong on 10 June 1977, Chinese Vice-Premier Li Xiannian charged that:

Urging Hanoi to stop involving local authorities in the border disputes, Li Xiannian reminded Pham Van Dong that “Comrade Deng Xiaoping told Comrade Le Duan [in September 1975] that the two sides should not listen to and follow the reports from local authorities at the border and that the top leaderships of the two Parties and Governments should decide this matter.”Footnote ⁹³ Pham admitted to Li that the Vietnamese government actually depended on “competent local authorities” to defend Vietnam's territorial integrity. However, he also pointed out:

Mirroring Beijing's view, Vietnamese leaders suspected that Chinese leaders were treacherously staging a diplomatic ploy, pretending eagerness to negotiate the border dispute to conceal a creeping expansionist policy.Footnote ⁹⁵ The head of the Vietnamese border negotiation team and Vice-Minister of Foreign Affairs Phan Hien was of the view that Beijing's real motive was to buy time for Chinese local authorities and border armed forces to grab more Vietnamese land illegally.Footnote ⁹⁶ Pham also charged that “there has been a wide spread campaign on the Chinese side of the border to spread rumors that Vietnam has sided with the Soviets to attack China.”Footnote ⁹⁷ Li admitted that there had also been a number of incidents provoked by Chinese local authorities, but that these were not China's policy, and promised that Beijing would take stricter measures to educate Chinese local authorities at the border areas to ensure that they would truly maintain the spirit of Sino-Vietnamese fraternal relations, and would not trespass into the Vietnamese side of the border.Footnote ⁹⁸

In actuality, Hanoi and Beijing continued to allow their local authorities to play an important role in preparing documentation of their territorial possessions allegedly seized by the other side. The result was that both sides’ local authorities frivolously claimed as much land as they could and listed as many cases of one another's incursions as they could possibly find before the negotiations even began, thus undermining any chance to ease tension and find solutions through negotiation. In the midst of this tit-for-tat land grabbing, the Vietnamese local authorities did more than their government asked for in the name of defending their territorial sovereignty by intimidating and frightening Chinese residents along the border areas, which sparked the first wave of ethnic Chinese fleeing across the border into China in the second half of 1977.

After several months of preparation, the Sino-Vietnamese border negotiations commenced in October 1977. However, they not only yielded no positive result, but also turned into a forum for divisive mutual accusations and protests. The negotiation in late 1977 took place in the context of rapidly deteriorating Sino-Vietnamese relations. Beijing reduced its economic and military aid to Hanoi and curtailed bilateral economic relations to a minimal level, while substantially increasing its economic and military aid to the anti-Vietnamese Democratic Kampuchea (DK). As a result, Vietnam feared being encircled by China and the Khmer Rouge in Cambodia. MOFA's July report stated that “in the past six months [of 1977], our diplomacy had to address very important issues with our allies as well as with our adversaries. Those are the issues related to our security, sovereignty, territorial integrity, international position and influence and the implementation of our five year economic plan [1976–1980].”Footnote ⁹⁹ With regards to DK–Vietnam relations, Hanoi also was facing increased military attacks by the Khmer Rouge along the border, while all attempts at negotiation failed in the second half of 1977.Footnote ¹⁰⁰ This intensified Hanoi's fear that Vietnam was being subjected to coordinated pressure from the north (China) and the southwest (the Khmer Rouge).

In Hanoi's view, the escalated territorial conflict with China and its ally the Khmer Rouge in 1977 posed a threat to the existence of the newly unified Vietnamese state. In addressing the Khmer Rouge issue, Hanoi appeared to believe that improved relations with Beijing would help reduce its tension with the DK because the Khmer Rouge's provocative actions had China's strong backing. The preparation for the October 1977 border negotiation with China received special attention at the top leadership of the Vietnamese government, directly involving the VCP Central Committee Politburo, important ministries and departments including Foreign Affairs, Defense, Interior, the State Map Department, down to People's Committees in communes along the Sino-Vietnamese border. Apparently, the Ministry of Defense and the Ministry of the Interior, the two powerful Vietnamese defense and security enforcement apparatus, played prominent roles in both the preparation for and participation in the negotiation with China, although the Ministry of Foreign Affairs served as head of the Vietnamese delegation. Thus, the military and police forces dominated and executed the preparation plan. In effect, this put the armed forces of both countries on high alert along both the land and water frontiers between the two countries.

On 5 July 1977, the Vietnamese Ministry of Foreign Affairs proposed that the Ministry of Defense, the Ministry of the Interior, and the Navy participate in the preparations for the upcoming border negotiations with China.Footnote ¹⁰¹ On 7 July, the Prime Minister's Office called for an urgent meeting to study and disseminate the Politburo's policy instructions regarding such preparation tasks, and discuss measures to be taken to implement the policy effectively.Footnote ¹⁰² The consensus was to entrust Vietnamese local authorities with the task of collecting evidence of China's encroachment cases, and any historical, physical, and documentary evidence of Vietnamese ownership of land illegally seized by the Chinese in the past. In addition, they were instructed to conduct constant surveillance on any suspicious Chinese activities on the other side of the border and directly report such incidents to the central government in Hanoi. On 7 July, the Prime Minister's Office passed down the following specific orders to the local Vietnamese authorities:

1. 1. Compile files concerning all new incidents [of Chinese encroachment] and any change in the boundary of the disputed territory, which has been concluded during the previous round of bilateral border marking.

2. 2. Collect all existing contracts and physical evidence and so forth as proof of our possession of the territory encroached upon by the Chinese.

3. 3. Take pictures of any territory encroached upon by the Chinese and any border markers removed by the Chinese side.

4. 4. Vigilantly and closely maintain surveillance over the situation in border areas, including the Chinese side's activities, and report them to the central government in timely fashion. From now until the date of the negotiations, you must strictly follow the instruction of the Party Central Committee to decisively defend our territorial integrity but avoid causing the kind of problems that the Chinese can use to blame us.Footnote ¹⁰³

On 25 July, MOFA proposed that the Vietnamese border negotiation delegation should consist of two high-ranking military officials who were experts on the land and maritime boundaries with China, and heads of the map and geological department. They were given responsibility to prepare documentary evidence. Nguyen Tien, head of the China Department at MOFA, was in charge of programming the upcoming border negotiations with China. Noticeably, the Ministry of Defense and the Ministry of the Interior were instructed to put together and review all documents on border issues from 1956 to 1977. The Defense Ministry was ordered to conduct surveillance flights along the border and produce photographic images in order to construct a border map and produce a complete report before September 1977.Footnote ¹⁰⁴

Shortly after that, the Prime Minister's Office instructed the People's Committees in all provinces along the Sino-Vietnamese border to inform local authorities of the Central Party's directive – that is, from July to the negotiation date in October, the People's Party Committees had to effectively carry out the crucial tasks of “educating local people, cadres, and armed forces, firmly defending their territory, and making all efforts to prevent [China's] acts of encroaching on our land or other violations by the Chinese side, but they shall avoid provoking incidents which China could use to lay blame on us.”Footnote ¹⁰⁵ The Defense Ministry and Interior Ministry were required to give clear instructions to all members of the armed forces under their authority to follow the Party Central Committee's directive accordingly.Footnote ¹⁰⁶ As a result, these local authorities were under increased pressure to produce urgent reports on Chinese incursion, having now become Hanoi's eyes and ears.

Underlying Vietnam's tit-for-tat struggle with the Chinese along the border was Hanoi's belief, as Phan Hien summarized in his report on 31 March 1978, that “China has no willingness to solve the border issue, but intends to use it to spread propaganda to arouse popular support inside and outside its country.”Footnote ¹⁰⁷ In the third round of negotiations from 12 to 24 January 1978, China raised a nine-point proposal (five from the second round of negotiations on 11 October 1978, and adding four new conditions concerning the issue of “maintaining the status quo” and other details about the 1887 Franco-Qing treaties).Footnote ¹⁰⁸ The nine-point proposal, as Phan Hien noted in his report to his leadership, primarily served China's interests in two ways: first, China attempted to use the historical border boundary to its advantage – although the Chinese spoke of using the 1887 Franco-Qing Treaty as the basis, in reality they drew a different boundary map to expand their claim over not only the territory occupied by Chinese people due to historical legacies but also Vietnam's territory that China had sent their people to occupy for many years. Second, China put forth the condition of “maintaining the status quo” to retain the territory they had recently taken from Vietnam, demanding that the latter share the river for fishing, give away part of the territory around the Sino-Vietnamese Friendship Pass, and so forth.Footnote ¹⁰⁹ Though Hanoi agreed to negotiate the land border issue first, Beijing, to the former's disappointment, refused to make any concession regarding the Paracel and Spratly islands, insisting that the two countries observe the principles agreed upon in the two parties’ declarative exchanges in 1957–1958. Phan Hien described the Chinese side's attitude throughout the negotiation process this way:

Phan Hien's report also requested that concerned authorities including the Ministry of Defense and the Ministry of the Interior take counter-measures regarding the issues of “maintaining the status quo before a bilateral agreement on the border boundary comes into effect” and “Chinese residents fleeing across the border to China.”Footnote ¹¹¹

As it turned out later, these counter-irredentist measures resulted in many cases of alleged discrimination and mistreatment of ethnic Chinese residents along the border, and sparked numerous border clashes. Neither Vietnamese nor Chinese leaders were willing to restrain their local authorities. In Vietnam, it was even more difficult and dangerous for any local Vietnamese leader to do so because they would be accused of being pro-Chinese or traitors. As a result, border clashes between local armed forces along the Sino-Vietnamese borders occurred more frequently and spiraled out of control. Beijing then criticized Hanoi for using local authorities for land grabbing, and vice versa. This profoundly intensified an atmosphere of insecurity and paranoia on both sides of the border, which in turn caused the flight of Chinese residents from northern Vietnam to China during 1977 and 1978.

It was the escalated border conflict and the Vietnamese government's growing concern about Chinese residents’ loyalty toward the Chinese government that drove Hanoi to accelerate swiftly the policy of forced assimilation of Chinese residents to “purify” the Vietnamese nation in 1977–1978. As Chinese residents resisted Hanoi's forced assimilation policy, Hanoi's suspicion of Chinese loyalty was confirmed and tough measures were then introduced: Chinese residents along the border were either forced to migrate to China or relocate to New Economic Zones against their will.Footnote ¹¹² In the midst of this chaotic atmosphere, local Vietnamese authorities’ harassment of ethnic Chinese residents along the border and their alleged expulsions continued unabated, precipitating and deepening the perception of fear and paranoia within the Chinese community across northern Vietnam. As it turned out, the mass exodus of Chinese residents along the border began in 1977. On 12 May 1978, in the Chinese Foreign Affairs Ministry's letter to the Vietnamese Embassy, Beijing protested that:

Hence, it is no coincidence that the mass exodus of Chinese residents from northern Vietnam coincided with the heightened territorial dispute between China and Vietnam. Hanoi's forced assimilation of Chinese residents that began in 1976 and the political discourse of “the threat from the North” were the ingredients of the Vietnamese state-sponsored nationalism to mold national unity and cohesion and mobilize domestic resources to confront the emerging threat from China. In hindsight, the fact that Chinese residents in northern Vietnam, especially in provinces along the] Sino-Vietnamese border, were easy targets of local Vietnamese authorities’ “scare campaign” to frighten them into fleeing from Vietnam into China is not difficult to comprehend. As discussed above, their loyalty, in Hanoi's view, lay with the Chinese state despite the fact that they resided in Vietnamese territory.

The result was a spiraling conflict with disastrous consequences. The number of border disputes rose from 100 cases in 1974 to over 400 in 1975 and to over 900 cases in 1976.Footnote ¹¹⁴ From July 1977 to March 1978, border clashes rose from a total of 1,625 reported by both sides to 2,175 reported by Vietnam and 1,108 reported by China in 1978.Footnote ¹¹⁵ Thus, the Sino-Vietnamese border was rapidly militarized. The fact that the number of border clashes in 1977 doubled from the previous year, and only slightly declined in 1978, clearly indicates how intensified the militarization of the border became in the short span of a few years. In this climate, Hanoi moved ethnic Chinese from border areas – other ethnic minorities including the Hmong, Dzao, Thay, and Nung were also affected – to create a militarized buffer zone. As a result, the mass exodus of Chinese residents from northern Vietnam into China also grew rapidly from late 1977 to mid-1978. Before the Sino-Vietnamese border war, 95 per cent of Chinese residents in northern Vietnam had already crossed the border into China. By early June of 1978, the number of refugees in China had reached 100,000. By mid-July, the total number exceeded 160,000. The earliest refugees were from provinces adjacent to China, but later, Chinese residents from other parts of northern Vietnam joined the flow. In mid-July 1978, China closed its border with Vietnam to stop the further influx of refugees, but small groups of people continued to enter. By February 1979, when China launched the three-week war against Vietnam, 202,000 refugees had already arrived in China.Footnote ¹¹⁶ There is no dispute that Hanoi's forced assimilation caused the flight of Chinese residents, but it is not the only cause. The intensified Sino-Vietnamese border dispute exacerbated by the radicalization of both sides’ domestic measures to lay claims over disputed territory along the border and the militarization of the border itself instilled a pervasive fear of persecution and harassment within the Chinese community in northern Vietnam, and gave free rein to local Vietnamese authorities to harass and persecute Chinese residents there. The parallel trend between the increased militarization of the border and the increased mass exodus of Chinese residents in northern Vietnam indicates the linkage between the two issues.