Reluctant neighbours or strategic partners? Cambodia-Vietnam political relations from history to the present

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Introduction

In the landscape of Southeast Asian international relations, few bilateral pairs are simultaneously as close and as complex as Cambodia and Vietnam. The two countries share a 1,137 km land border, lie within the lower Mekong basin, and were jointly subjected to French colonial rule [Lê Thị Bình 2022]. Such affinities might have been expected to furnish a durable foundation for cooperation. In practice, the relationship has always carried tensions resistant to resolution — from centuries of territorial contestation and the trauma of the Khmer Rouge period to an ethnic wariness not yet entirely overcome [Co et al. 2025].

Scholarly attention to this relationship has grown steadily over the past three decades, though the literature remains uneven. McHale [2013] traces Khmer–Vietnamese ethnic relations across nearly two centuries; Mosyakov [2005] and Bektimirova [2019], drawing on Soviet archives, illuminate the ideological dimensions of the 1978–1979 conflict and complicate the liberation-versus-invasion binary that continues to divide Cambodian society. Heder [2018] offers the most rigorous examination of the Cambodian People’s Party (CPP) – Communist Party of Vietnam (CPV) institutional relationship, showing how both parties deploy the concept of “hostile forces” as a tool of regime security. Heng [2022] provides the most balanced account of outstanding bilateral issues and notes candidly that competing memories of 7 January 1979 continue to fracture Cambodia’s domestic politics. Var [2021] argues that Cambodia’s deepening alignment with China has created structural tensions with Vietnamese interests that condition the limits of cooperation within the Association of Southeast Asian Nations (ASEAN). Canzutti [2019] links bilateral politics to the lived reality of Vietnamese statelessness in Cambodia, while Burova [2025] questions whether deepening economic integration delivers genuinely symmetric benefits to both sides. Vietnamese scholarship — including Lê Thị Bình [2022] and Nguyễn Minh Tâm and Hồ Quỳnh Phương [2021] — provides valuable documentation of formal bilateral frameworks, though typically within an optimistic register that gives limited attention to structural asymmetries or anti-Vietnamese nationalism in Cambodian society.

Taken together, this body of scholarship reveals a field that has advanced considerably on individual dimensions — historical, institutional, or geopolitical — while struggling to hold them in view simultaneously. Studies grounded in party politics tend to underplay structural economic asymmetries; those focused on border demarcation rarely engage with the broader regional security context; and Vietnamese-language scholarship, however rich in documentary detail, has been slow to reckon with the nationalist currents that complicate the official narrative. This article attempts to address that unevenness. Drawing on primary diplomatic documents and secondary sources in English, Vietnamese, and Russian, it argues that while the strategic logic binding the two states together remains robust, the relationship’s long-term durability depends on confronting unresolved foundational issues and building trust at the people-to-people level — something that high-level diplomacy alone cannot substitute for.

Taken together, this body of scholarship reveals a field that has advanced considerably on individual dimensions — historical, institutional, or geopolitical — while struggling to hold them in view simultaneously. Studies grounded in party politics tend to underplay structural economic asymmetries; those focused on border demarcation rarely engage with the broader regional security context; and Vietnamese-language scholarship, however rich in documentary detail, has been slow to reckon with the nationalist currents that complicate the optimistic official narrative. This article attempts to address that unevenness. Drawing on primary diplomatic documents and secondary sources in English, Vietnamese, and Russian, it argues that while the strategic logic binding the two states together remains robust, the relationship’s long-term durability depends on confronting unresolved foundational issues and building trust at the people-to-people level — something that high-level diplomacy alone cannot substitute for.

Historical Foundations and the Trajectory of Diplomatic Normalization

The history of relations between the Vietnamese and Khmer peoples stretches across centuries, comprising layers of cooperation, competition, and conflict. From the seventeenth century onward, as the Khmer Kingdom weakened under simultaneous pressure from Thailand (then called Siam) and Vietnam (then called Đại Việt), Vietnamese migration and territorial expansion into the Mekong Delta unfolded gradually — absorbing formerly Khmer territories in a process of incremental demographic and administrative encroachment rather than outright conquest. That distinction matters: the grievance it left behind is diffuse and unanchored to any single negotiable event, which is part of why it has proven so resistant to resolution. The historical picture is not, however, one of unrelieved antagonism. The first formal relations between the two sides date to the early seventeenth century, when Cambodian King Chey Chetha II married a Vietnamese princess, opening durable demographic ties alongside territorial vulnerability — a combination that has characterized the relationship ever since [Nguyen et al. 2024].

The French colonial period (1858–1954) placed both countries within the Indochinese Union while planting legal ambiguities that would outlast the empire. Most consequentially, the Brévié Line of 1939 — drawn as an administrative demarcation for the islands of the Gulf of Thailand — was explicitly qualified at the time of its creation: Governor-General Brévié’s letter of 31 January 1939 stated that “this concerns only matters of administration and policing; the question of the territorial attribution of these islands is entirely reserved” [Nguyễn Minh Ngọc 2010]. By leaving sovereignty deliberately unresolved, France handed its successor states a boundary instrument whose ambiguity was guaranteed to generate dispute. Cambodia has since demanded the Brévié Line as the official maritime boundary; Vietnam rejects this and proposes the median-line principle under United Nations Convention on the Law of the Sea (UNCLOS) — a disagreement rooted not in bad faith but in a shared colonial inheritance neither side chose.

The national liberation movements against France and later American intervention created a layer of solidarity that made formal diplomatic relations possible. During Norodom Sihanouk’s period as Head of State (1955–1970), Cambodia maintained neutrality while tacitly supporting the Vietnamese resistance [Thông tin cơ bản… 2006], and the 1965 Conference of the Peoples of the Indochinese Nations formally affirmed this solidarity. On 24 June 1967, the Democratic Republic of Vietnam and the Kingdom of Cambodia established diplomatic relations — an event President Hồ Chí Minh described as a “brilliant expression of close friendship and fighting solidarity” [Lê Thị Bình 2022]. The relationship was born from shared resistance, which is precisely why its subsequent rupture proved so devastating.

The coup of 18 March 1970 set in motion a chain of radicalization whose endpoint was the seizure of power by Pol Pot’s Democratic Kampuchea on 17 April 1975. The Khmer Rouge killed approximately 1.7 million Cambodians — roughly 20 per cent of the population — through execution, forced labour, and engineered famine [Mosyakov 2005]. Crucially for bilateral relations, the regime did not confine its violence internally: it launched systematic attacks against Vietnam under the banner of extreme ethno-nationalism, massacring thousands of Vietnamese civilians in the southwestern border provinces, most notoriously at Bà Chúc in April 1978 [Bektimirova 2019]. It was this external aggression that transformed an internal Cambodian catastrophe into a direct security threat to Vietnam and provided the rationale for intervention.

Vietnamese forces launched a counteroffensive on 23 December 1978 in coordination with the Kampuchean National United Front for National Salvation, entering Phnom Penh on 7 January 1979 and ending the Pol Pot regime. The event has never been interpreted the same way on both sides of the border. Vietnam and the CPP-led People’s Republic of Kampuchea call it “Liberation Day”; a significant portion of the Cambodian population and most Western analyses describe it as an invasion and occupation lasting until 1989. As Heng [2022] observes, these competing readings have generated “divisions rather than unity, hostility rather than harmony” within Cambodian society — and they continue to do so, providing a recurring resource for political actors who find it useful to associate the CPP with Vietnamese influence.

Following the withdrawal of Vietnamese forces in September 1989 and the Paris Peace Agreements of 23 October 1991, normalization proceeded gradually. Cambodia joined ASEAN in 1999, four years after Vietnam’s 1995 accession, giving both countries a shared multilateral framework. Since then, the relationship has developed under the official formula of “good neighbourliness, traditional friendship, comprehensive cooperation, and long-term sustainability” [Thông tin cơ bản… 2006] — a phrase that captures genuine aspiration while quietly acknowledging that the work of reconciliation remains incomplete.

Mechanisms of Political–Security Cooperation in the Contemporary Period

What distinguishes Cambodia–Vietnam relations from most bilateral relationships in the region is the central role played by party-to-party ties. This is not merely a government-to-government relationship but a political linkage between the CPP and the CPV forged during years of shared struggle — one whose depth derives from the fact that it was built under conditions of existential threat rather than routine diplomacy. Many senior CPP leaders, including Hun Sen, had sought refuge in and received support from Vietnam during the anti-Pol Pot years, creating personal obligations that have since been institutionalized into structural ties. In 2017, Hun Sen visited Vietnam and expressed gratitude for “the sacrifice that Vietnam made for Cambodia,” and expressed the wish that bilateral solidarity “may remain forever green and enduringly durable” [Trần Văn Thông 2017]. Heder [2018] ranks the CPP as the second-highest priority foreign political organization for CPV cooperation — after Laos only — a prioritization reflecting the CPV’s view that political stability in Cambodia is a prerequisite for Vietnam’s own security.

These ties have been institutionalized in regular meeting mechanisms, most notably the summit between the Politburo of the CPV Central Committee and the Standing Committee of the CPP Central Committee — a format rare in regional international relations. From early 2025 to February 2026 alone, the two sides recorded ten visits and high-level contacts. During General Secretary Tô Lâm’s state visit to Cambodia in February 2026 — his first foreign trip after the CPV’s 14th National Congress — he co-chaired both a bilateral party meeting and a trilateral CPV–CPP– Lao People’s Revolutionary Party (LPRP) meeting. The choice of Cambodia as the first destination was not incidental: Ambassador Nguyễn Minh Vũ noted that it “reflects the orientation and position of the Party and State in always attaching importance to relations with Cambodia” [Đưa quan hệ… 2026].

Security and defence remain the relationship’s principal pillar. From 1980 to 2016, Cambodia sent nearly 17,000 military personnel to Vietnam for training; by July 2015, nearly 6,000 Cambodian police officers had graduated from Vietnam’s Security Academy II [Heder 2018]. Between 2014 and 2016, Vietnam provided at least USD 29 million in defence assistance [Ibid.]. The numbers, however, only partially capture the relationship’s depth. As Heder demonstrates, both the CPP and the CPV deploy the concept of “hostile forces” — kamlang amit in Khmer, thế lực thù địch in Vietnamese — to describe movements they regard as threatening regime stability, extending beyond border security to encompass opposition parties, civil society organizations, and democratic movements. This shared threat perception gives the bilateral security relationship its distinctive character: it is simultaneously a conventional defence arrangement and a compact between two ruling parties with convergent interests in political survival.

This does not mean Vietnam controls Cambodia. As Pribbenow has observed, Vietnam “shares and supports Hun Sen’s views on the Cambodia National Rescue Party (CNRP)” and retains a degree of influence over the Cambodian government, yet does “not have significant control over Hun Sen and the CPP” [Heder 2018]. The clearest evidence is Cambodia’s position on the South China Sea: on two occasions — in 2012 and 2016 — Phnom Penh blocked ASEAN from issuing a joint communiqué critical of China, a position Hanoi wanted changed but could not change [Var 2021]. The CPP depends on Vietnam for regime legitimacy and security support, yet depends on China for economic resources and diplomatic cover — and when these interests pull in different directions, Vietnam does not always prevail.

At the institutional level, cooperation operates through multiple channels: the Joint Committee on Economic, Cultural, Scientific, and Technical Cooperation; the Conference on Cooperation and Development of Border Provinces; and frameworks within ASEAN, the Greater Mekong Subregion, the Mekong River Commission, and Ayeyawady–Chao Phraya–Mekong Economic Cooperation Strategy. At the sub-regional level, the Cambodia–Laos–Vietnam (CLV) trilateral framework had for decades represented the most concrete expression of shared development interests through the CLV Development Triangle Area, established in 1999. In September 2024, however, the Cambodian government officially withdrew from the CLV framework, motivated in part by concerns that opposition groups might exploit the agreement to stir nationalist sentiment domestically [Niem Chheng 2024]. The withdrawal is not a peripheral development: it removed a distinctive institutional layer from the bilateral architecture and signaled that the CPP’s domestic political calculations can override regional cooperation logic even when the strategic case for continued participation remains strong.

The economic relationship has grown substantially. Bilateral trade rose from approximately USD 130 million in 1997 to a record USD 11.33 billion in 2025, an increase of 11.7 per cent over the previous year [Đưa quan hệ… 2026]. By 2025, Vietnam ranked among Cambodia’s five largest foreign investors with nearly USD 3 billion in registered capital, distributed across virtually all major economic sectors. Metfone — Viettel’s Cambodian joint venture — entered the group of five enterprises making the largest contributions to the Cambodian state budget [Tran Hung 2026]. Vietnam has become Cambodia’s largest tourism partner, with over 1.2 million Vietnamese visiting Cambodia and nearly 690,000 Cambodians visiting Vietnam annually.

These are real achievements, and the economic interdependence they reflect does generate pressure to keep political relations stable. Yet the composition of trade matters as much as its volume. As Burova [2025] shows, Cambodia predominantly exports raw agricultural commodities to Vietnam for processing and re-export, capturing relatively little of the value added along the chain. The result is a pattern of integration that, however mutually convenient, leaves Cambodia structurally exposed — and one that, if left unaddressed, risks feeding the nationalist narrative that the relationship benefits Vietnam more than Cambodia. Shifting this pattern through Vietnamese investment in Cambodian processing and value-added industries is therefore as much a political question as it is an economic one.

Outstanding Issues and Structural Challenges in the Bilateral Relationship

Notwithstanding the advances in bilateral cooperation, several deep structural issues remain unresolved — and understanding them clearly is a prerequisite for any realistic assessment of the relationship’s prospects. Some of these challenges come into sharper focus when set alongside Cambodia’s concurrent territorial dispute with Thailand, which shares enough structural features with the Cambodia–Vietnam situation to serve as a cautionary parallel.

The land border demarcation process has been one of the most contentious issues in the relationship. The 1,137 km border rests primarily on French colonial-era maps, and the process of surveying and planting boundary markers on the ground has stretched over decades. By 2025, when the two countries signed a Supplementary Treaty and Protocol on demarcation results, 84 per cent of the land border had been completed — leaving 16 per cent as a permanent source of localized dispute. The political sensitivity of this issue was illustrated in July 2020 when trade union leader Rong Chhun was arrested after raising concerns about alleged irregularities in the demarcation process and claiming that some Cambodian farmers had lost land as a result. He was sentenced to two years in prison for “inciting serious social disorder” [Heng 2022], and some twenty young activists were arrested for protesting his detention. The government’s response — criminal prosecution rather than public rebuttal — reflected an anxiety that open debate on the border could rapidly become a vehicle for broader anti-Vietnamese sentiment.

Maritime delimitation in the Gulf of Thailand presents a different but equally intractable problem. Cambodia has consistently demanded the Brévié Line as the official sea boundary; Vietnam rejects this and proposes the median-line principle under UNCLOS [Nguyễn Minh Ngọc 2010]. On 7 July 1982, the two sides signed an Agreement on Historic Waters agreeing to treat the Brévié Line as the division of islands in the zone, while deferring the broader boundary question to future negotiation [Ibid.]. Technical rounds in 1998 and 1999 produced no breakthroughs, and the issue remains unresolved. The difficulty is that both sides can draw on the same colonial instrument to support their respective legal positions — making this less a problem of political will than one of genuine legal ambiguity, and therefore harder to resolve through negotiation alone.

The Vietnamese community in Cambodia constitutes a distinct and sensitive challenge. The figures alone tell a story of legal precarity: Cambodia’s 2019–2020 national census recorded approximately 27,477 ethnic Vietnamese, representing 0.2 per cent of the population, while other estimates range from 110,000 to as high as 700,000, with the majority reportedly lacking birth certificates or identity documents [Heng 2022]. In 2019, Cambodia relocated 4,563 households from floating homes on the Tonle Sap river in Kampong Chhnang province, 54 per cent of them Vietnamese, to a designated 40-hectare plot of land [Ibid.]. The move drew immediate criticism from opposition forces accusing the CPP of ceding land to the Vietnamese — illustrating how the presence of the community, and government decisions concerning it, can be quickly weaponized in domestic politics. The issue is not the community’s existence but its availability as a recurring instrument of nationalist mobilization whenever political actors find it useful.

Nationalism and divided historical memory remain the deepest and least tractable challenge. During the period of 2012–2017, the Cambodia National Rescue Party (CNRP) exploited border disputes and the Vietnamese community issue to attack the CPP, accusing the government of surrendering Cambodian territory [Canzutti 2019]. CNRP leaders inspected disputed border areas, made specific allegations about boundary marker irregularities, and in June 2015 led a delegation of approximately 2,000 people to a disputed site in Svay Rieng province, triggering altercations with villagers and Vietnamese security forces [Heder 2018]. The CPP’s dissolution of the CNRP by court order in November 2017 removed the principal organized vehicle for this narrative, but not the sentiment behind it. The competing interpretations of 7 January 1979 — Liberation Day or Day of Invasion — remain live political positions, rather than merely historical disagreements, and Heng [2022] notes that the CPP has in recent years quietly scaled back the anniversary’s public commemoration, distancing itself from a discourse too closely tied to Hun Sen’s legacy and the Vietnamese connection ahead of a generational leadership transition.

The Cambodia–Thailand border conflict offers an instructive parallel. The Preah Vihear dispute — rooted in the same French colonial cartographic ambiguities underlying Cambodia’s disagreements with Vietnam — escalated in July 2025 into the most serious armed confrontation between the two countries in decades, with fighting across approximately 800 km of contested border producing at least 38 deaths and displacing more than 300,000 people within five days before a ceasefire was brokered by Malaysian Prime Minister Anwar Ibrahim in his capacity as ASEAN Chair [Bong 2026]. Three features of this escalation are directly relevant to the Cambodia–Vietnam relationship.

First, it demonstrates what unresolved colonial-era territorial ambiguities can become when domestic incentives for nationalist mobilization are strong and institutional constraints are weak. The Cambodia–Vietnam relationship contains the same basic ingredients: incomplete demarcation, a disputed maritime boundary derived from an ambiguous colonial instrument, and a minority community that functions as a recurring political flashpoint. None of these has yet produced armed conflict, but the Thailand case is a reminder that the distance between managed tension and open confrontation can be shorter than it appears.

Second, the two cases diverge in the role of great-power competition. In the Cambodia–Thailand dispute, Cambodia’s alignment with China and Thailand’s position within the U.S. security architecture transformed a bilateral territorial conflict into a theatre in which Beijing and Washington each advanced competing narratives [Bong 2026]. The Cambodia–Vietnam relationship faces a version of the same risk: as Vietnam’s strategic positioning becomes more explicitly aligned with a rules-based regional order and Cambodia’s dependence on China deepens, the bilateral relationship carries growing potential to become a fault line in Sino–American competition rather than remaining an autonomous partnership.

Third, the conflict exposed the limits of ASEAN’s capacity to manage intra-member territorial disputes. The organization’s consensus requirement, its noninterference norm, and the absence of any enforcement mechanism mean that its ability to prevent escalation depends more on the personal authority of an active chair and the coincidental alignment of great-power interests than on institutional design. That is a fragile basis upon which to rest conflict prevention — and the observation applies equally to any future deterioration in Cambodia–Vietnam relations.

Cambodia’s broader strategic orientation compounds these vulnerabilities. Beijing is now Phnom Penh’s largest aid provider, investor, and trading partner, and this dependence shapes Cambodian foreign policy in ways that periodically cut against Vietnamese interests — most visibly on the South China Sea. As Heng [2022] notes, Cambodia “needs to manage its relations with Vietnam carefully so as not to alienate China” — a calibration that must be performed continuously and that becomes more difficult as China’s leverage over Phnom Penh deepens.

Prospects and Orientations for Development in the New Context

Despite the challenges outlined above, there are real grounds for measured optimism about Cambodia–Vietnam relations — provided that optimism is honest about what remains unresolved. Both states have powerful reasons to keep the relationship functional. Vietnam needs Cambodia to be a stable neighbour that cannot be used as a strategic platform against it. Cambodia needs Vietnam as an economic partner and a partial counterweight against the pressures that come with deep dependence on any single external patron. The principle, affirmed repeatedly by leaders on both sides, that “the peace, stability, and development of one country is also the peace, stability, and development of the other” [Đưa quan hệ… 2026] is not merely diplomatic language — it reflects a geopolitical reality that neither government can afford to ignore.

On trade and investment, the trajectory is upward and the targets are ambitious. Leaders have agreed to increase bilateral trade to USD 20 billion, and infrastructure projects currently under development — including a motorway linking Phnom Penh with Hồ Chí Minh City and a maritime route between Kampot and Phú Quốc — will deepen connectivity further. But the sustainability of economic integration as a stabilizing force depends on whether ordinary Cambodians experience it as beneficial rather than extractive. The structural imbalance Burova [2025] identifies — Cambodia exporting raw commodities while Vietnam captures the processing gains — will not correct itself. Vietnamese investment in Cambodian processing and value-added industries would serve both sides: it would broaden Cambodian participation in the economic relationship and reduce the political traction of the narrative that Vietnam takes more than it gives. This is the kind of structural adjustment that makes a trade target meaningful rather than merely symbolic.

On the border, both sides need a concrete roadmap with clear timelines for completing the remaining 16 per cent of land demarcation, accompanied by transparent public communication that frames completion as sovereignty protection rather than concession. The Cambodia–Thailand experience makes the cost of delay vivid: the Preah Vihear dispute festered across more than six decades — surviving the International Court of Justice’s 1962 ruling, the 2008–2011 armed confrontations, and the 2013 interpretative judgment — before erupting in July 2025 into the most destructive episode yet [Bong 2026]. Cambodia and Vietnam have an interest in not repeating that trajectory. The 2012 inauguration of boundary marker 314 — completed on the occasion of the 45th anniversary of diplomatic relations — showed that when political will is present, progress is achievable [Nguyễn Minh Tâm, Hồ Quỳnh Phương 2021]. The challenge is sustaining that will between symbolic milestones rather than mobilizing it only for them.

On historical memory, the path forward runs through academic dialogue rather than official commemoration. As Heng [2022] suggests, leaders on both sides should resist the temptation to control the meaning of 7 January 1979 and instead leave the debate to historians capable of engaging with it on evidentiary rather than political grounds. Genuine reconciliation does not require agreement on a single narrative — it requires the willingness to acknowledge complexity without weaponizing it. The Cambodia–Thailand experience is cautionary here too: the entanglement of the Preah Vihear dispute with competing national narratives about Khmer cultural heritage made the conflict progressively harder to de-escalate, because political actors on both sides had invested too much in their respective versions of history to accept compromise without loss of face [Bong 2026]. Keeping historical dialogue in academic rather than political hands is not a counsel of evasion but of practical wisdom.

On the Vietnamese community in Cambodia, what is needed is a clear and transparent immigration framework establishing specific criteria for citizenship or long-term residency for those who have lived in Cambodia for generations and satisfy defined conditions. This is a humanitarian question, but it is also a stabilizing one: the community’s persistent legal precarity keeps it available as a tool of nationalist mobilization. Resolving it would deprive nationalist actors of one of their most reliable mobilization tools. As Canzutti [2019] notes, doing so requires political will from both sides and engagement from a wide range of stakeholders — officials, historians, civil society, and community representatives — not merely administrative reclassification.

On the broader strategic environment, both Cambodia and Vietnam share an interest in keeping ASEAN functional enough to provide some institutional buffer against the most disruptive effects of great-power competition. Their views on China and the South China Sea diverge significantly, and those divergences will not disappear. But the shared interest in preventing Southeast Asia from becoming an arena of unmediated great-power confrontation — illustrated negatively by the multipolar scramble over the Cambodia–Thailand ceasefire in July 2025 — provides a basis for quiet coordination even when public alignment is impossible.

Ultimately, the relationship’s durability depends on more than governments and parties. People-to-people ties require deliberate cultivation. Approximately 3,000 Cambodian students currently study in Vietnam, while around 100 Vietnamese students study in Cambodia [Sinh viên Campuchia… 2025]. These exchanges are a beginning, but expanding them — through youth programmes, media cooperation, and joint cultural initiatives — is the only way to build the kind of societal foundation that can survive changes in government, shifts in great-power alignment, and the inevitable evolution of the party-to-party relationship that has so far been the bilateral relationship’s primary anchor.

Conclusion

Nearly six decades after the establishment of diplomatic ties, Cambodia–Vietnam relations remain what they have always been: a relationship shaped in equal measure by geopolitical necessity and historical burden. The two countries have built something real — dense institutional ties, growing economic interdependence, and a shared interest in regional stability that neither can afford to discard. But the relationship’s resilience has been sustained partly by deferring its hardest questions rather than confronting them.

The incomplete border demarcation, the unresolved maritime dispute, the imbalance in the trade structure, and the divided memory of 7 January 1979 are not simply legacy issues awaiting administrative resolution. Each remains capable of being exploited by domestic political actors or drawn into the broader currents of great-power competition when conditions align. Cambodia’s September 2024 withdrawal from the CLV trilateral framework — driven by domestic anxiety about nationalist backlash rather than any diminution of shared regional interests — is a recent illustration of how quickly political calculations can override cooperative logic. The July 2025 Cambodia–Thailand escalation is a starker one: a reminder that unresolved colonial-era territorial ambiguities, left to interact with nationalist mobilization and external strategic competition, can detonate with devastating speed.

What the relationship needs is less diplomatic ceremony and more structural work — completing the border demarcation process, rebalancing trade, regularizing the legal status of Vietnamese residents in Cambodia, and creating genuine space for historical dialogue that neither government controls. The current high tempo of bilateral engagement suggests that both sides understand this. Whether that understanding translates into action on the difficult questions, rather than continued investment in the easier ones, is where the relationship’s future will be decided.

About the authors

Thi Thanh Van Nguyen

Ho Chi Minh National Academy of Politics

Author for correspondence.
Email: thanhvan020980@gmail.com
ORCID iD: 0009-0005-6850-471X

Ph.D (Political Studies)

Viet Nam, Hanoi

Thu Ha Nguyen

Ho Chi Minh National Academy of Politics

Email: thuhanguyen1801@gmail.com
ORCID iD: 0009-0000-5489-1652

Ph.D (Political Studies)

Viet Nam, Hanoi

Xuan Hiep Tran

The University of Da Nang, University of Science and Education

Email: txhiep@ued.udn.vn
ORCID iD: 0000-0002-5236-993X

Associate Professor, Ph.D (Political Studies)

Viet Nam, Da Nang

References

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