Fighting has intensified along the Thailand-Cambodia border despite US President Donald Trump's claim of a renewed ceasefire, with airstrikes, rockets and mass displacement reported. Historical territorial disputes, domestic politics and competing narratives over responsibility complicate mediation efforts. Over the next decades, outcomes range from a negotiated settlement that strengthens ASEAN conflict-management norms to a lingering low-intensity conflict that periodically disrupts regional stability, trade and human security.
Verdict: Recent reporting shows heavy fighting along the Thailand-Cambodia border despite Trump's announcement of a renewed ceasefire, with both governments disputing his claims and accusing each other of ongoing attacks (AP, 2025-12-13; Reuters, 2025-12-13; Washington Post, 2025-12-13). Casualties are reported on both sides and hundreds of thousands have been displaced, while ASEAN-led mediation remains fragile (Al Jazeera, 2025-12-13; Euronews, 2025-12-13). Historical disputes over maps and temple areas, combined with domestic political incentives, suggest that without sustained monitoring, guarantees and economic carrots, the risk of a drawn-out, low-intensity war is significant.
Within one to two years, international and ASEAN pressure secures a durable ceasefire with joint border commissions, demilitarised zones and third-party monitoring. Both governments reframe the dispute as a technical demarcation issue rather than an existential struggle. Cross-border trade, infrastructure and tourism slowly resume, and the conflict becomes a catalyst for stronger ASEAN conflict-prevention norms.
The conflict settles into cycles of flare-ups and uneasy truces over the next decade. Casualties and displacement accumulate but remain mostly localised, while diplomatic efforts prevent large-scale escalation. Domestic political actors in both countries use the dispute for nationalist mobilisation, slowing but not blocking gradual movement toward a negotiated arrangement.
Escalation spirals beyond the border, drawing in heavier weaponry, cyber operations and proxy involvement. A miscalculation or major incident, such as a strike on a populated city or critical infrastructure, forces broader mobilisation. ASEAN proves unable to manage the crisis, straining regional unity and scaring off investment for years.
An unexpected political shift-such as leadership change, domestic upheaval or a landmark international court ruling-reframes incentives rapidly. One or both sides could pivot to a grand bargain involving security guarantees, resource-sharing and cultural heritage agreements. Alternatively, external great-power competition could turn the border into a testing ground for new military technologies or security pacts, altering regional order.
Developments: In 2026, additional rounds of talks and ceasefire declarations are likely, some of them public and others quiet. Small buffer zones or pullbacks may be agreed in limited sectors while other hotspots remain contested. Humanitarian agencies scale up support for displaced people and host communities, though access fluctuates with security conditions.
Risks: Misinterpreted troop movements, artillery incidents or accidents can quickly unravel local truces. Domestic political incentives may favour hard-line rhetoric over compromise, limiting space for de-escalation. Disinformation campaigns or inflammatory media coverage can inflame public opinion, reducing leaders' flexibility.
Outlook: The most probable outcome is a patchwork of tense calm and periodic skirmishes. Humanitarian needs stay high along the border. Diplomatic actors focus on preventing major escalation rather than resolving root causes.
Developments: By 2027, the parties may have established more structured joint commissions on demarcation, refugees and incident prevention, often under ASEAN auspices. Back-channel contacts explore face-saving formulas that link security steps to economic incentives. Local ceasefire monitoring mechanisms involving community leaders and security officials might emerge in some districts.
Risks: If talks are perceived as one-sided or illegitimate, spoilers in either military or political elites could sabotage them. Continued displacement without durable solutions may radicalise some border residents. A parallel crisis elsewhere in the region could divert diplomatic attention and resources away from this dispute.
Outlook: The central expectation is slow institutionalisation of conflict-management tools without a final settlement. Fatigue on all sides may reduce intensity but not eliminate the risk of renewed fighting. Progress will depend heavily on credible monitoring and shared economic interests.
Developments: Around 2028, elites in both countries face clearer costs of continued conflict in terms of budgets, trade losses and reputational damage. International financial institutions and partners may condition some support on de-escalation benchmarks. Track-two dialogues among academics, religious leaders and business groups help identify mutually beneficial arrangements.
Risks: If domestic politics in either country reward uncompromising stances, leaders may double down on militarisation. An isolated large incident with many civilian casualties could reset relations to maximum hostility. Lack of accountability for abuses may entrench impunity and grievances in affected communities.
Outlook: The baseline path remains a frozen but occasionally hot conflict with thin layers of cooperation. However, by this stage the structural incentives for a negotiated framework are stronger. A carefully sequenced package of security, justice and development measures could shift trajectories if political windows open.
Developments: By 2030, some segments of the border may be relatively stabilised, with joint patrols, regulated crossings and basic services restored. Other stretches could remain heavily militarised and economically depressed. Regional connectivity projects may bypass unstable areas, reinforcing uneven development.
Risks: Persistent insecurity can foster criminal networks, trafficking and illicit resource extraction in poorly governed zones. Inadequate attention to land rights, restitution and compensation may entrench dispossession. If climate impacts worsen, competition over water, forests and arable land could intersect with unresolved grievances.
Outlook: Most likely, the conflict's footprint shrinks geographically but deepens where it persists. People in stabilised corridors benefit from renewed commerce, while others remain trapped in cycles of poverty and violence. Long-term peace will hinge on inclusive governance and accountable security institutions.
Developments: By 2035, the handling of this dispute will significantly influence perceptions of ASEAN's capacity to manage intra-regional conflicts. If partial settlements hold, ASEAN may codify new mechanisms for monitoring, sanctions and dialogue. The border area could either evolve into a symbol of successful regionalism or a reminder of its limitations.
Risks: Failure to resolve core issues may encourage other states with territorial disputes to rely more on unilateral actions and external patrons. Militarised nationalism could become entrenched in education and media, making compromise harder. External powers might exploit divisions for strategic footholds, complicating regional security architectures.
Outlook: Under the baseline, ASEAN's role is judged as mixed: effective at capping escalation but weak at enforcing durable solutions. The conflict remains a cautionary tale but not a fully transformative crisis. Regional stability is preserved but not deepened.
Developments: By 2045, the Thailand-Cambodia border conflict will serve as a key precedent for how Southeast Asia handles overlapping sovereignty, heritage and resource disputes. If substantial agreements were reached, joint development zones, shared heritage management and co-governed conservation areas may be operating. Younger generations may view the conflict as history rather than an active grievance.
Risks: If grievances remain unresolved, periodic incidents could still spark violence, especially during political transitions or economic downturns. Marginalised border populations may continue to experience discrimination, underinvestment and security abuses. Broader regional crises, including climate or economic shocks, may revive competition over contested territories.
Outlook: The most likely outlook is a gradual move from active conflict toward imperfect normalisation. Deep reconciliation is possible but not guaranteed. Whether the episode strengthens or weakens norms against interstate violence in ASEAN will be central to its legacy.
Developments: By 2075, the conflict's legacy will be embedded in either a more integrated, peaceful Southeast Asia or a region marked by recurring border tensions. Education, memorialisation and local governance arrangements will shape how future generations interpret the war and its resolution. Institutions created in response-such as stronger ASEAN security bodies or cross-border councils-may have evolved or been replaced.
Risks: If underlying narratives of victimhood and betrayal persist, political entrepreneurs could periodically revive the dispute for domestic gain. Environmental change, including shifting rivers or coastlines, may reopen demarcation questions. Technological and military advances could alter deterrence dynamics, introducing new escalation pathways.
Outlook: Given long time horizons, only broad tendencies are plausible: either institutional learning reduces the role of interstate violence in the region, or unresolved grievances keep the door open to renewed crises. The treatment of affected communities and transparency of past settlements will strongly influence which path prevails.