The border tension between Preah Vihear Temple and its border peripheral zones has been an open wound between Cambodia and Thailand. Its genesis is colonial cartography, particularly in the 1904 and 1907 Franco-Siamese treaties mapping the frontier between French Indochina and Siam, and in the ICJ’s 1962 decision that the temple complex belonged to Cambodia. But the larger border perimeter remained unmarked and contested.
By 13 February 2025 tensions had already arisen as Thai troops prevented Cambodian tourists from singing the Cambodian national anthem close to the location of the nearby temple. The action released nationalist bravado on both sides and showed that the conflict was transitioning from latent to active. On 28 May 2025, a skirmish close to the Chong Bok pass led to the death of a Cambodian soldier. That growth led to a dramatic escalation. Cambodia threatened to take the matter to the ICJ, and Thailand deployed additional troops and declared the situation a national security emergency. The crisis point began from July 24, 2025, onward, when there was naked artillery, rocket exchange, and air strikes at some points along the 817 km border.
The two sides accused each other of atrocities, and civilians were displaced in large numbers. ASEAN moved in as regional facilitator during international outrage. ASEAN Foreign Ministers, issuing a July 27, 2025, statement, appealed to the two countries to stop fighting and return to negotiations. The two governments, by July 28, 2025, committed to an unconditional ceasefire facilitated in Malaysia. Subsequently, there were August and September gatherings to monitor and solidify the cease-fire. This window of potential détente is a moment for more introspection. The fact that two ASEAN members spent so long on the verge of open war raises a question about whether the region’s conflict-management system is adequate. This article is composed with an eye toward seeing just how strong the commitment is, how weak the mechanism is, and what, if anything, would have to change if ASEAN is going to be able to meaningfully operate as a regional peace architect.
Commitment to Ending the Dispute
Cambodia and Thailand have both made public guarantees of ending the dispute and taking the negotiations forward. Following the July clash and the attempts at mediation, on August 7, 2025, a Kuala Lumpur joint statement witnessed agreement to allow ASEAN observers to oversee troop withdrawals and cease-fire. Additionally, the two countries, via their General Border Committee (GBC), met in Koh Kong province on September 10, 2025, co-chaired by Cambodian Defence Minister Gen. Tea Seiha and his Thai counterpart, Gen. Nattaphon Nakphanit.
There they pledged to withdraw heavy weapons back to regular installations, boost communication, and solidify mutual trust among border people. The mediation function of ASEAN is also significant. In August, the ASEAN Malaysian Chairmanship assumed the responsibility of coordinating the head of the observation team under an ASEAN-led observer mission. Despite such positive indications, the solidity of the pledge remains to be questioned. All national governments continue to give precedence to sovereign rights, and Thailand, for example, has wanted to maintain negotiations bilaterally and mediated by only neighbors and not an obligation-based multilateral process. The question then is whether these promises are abiding and turn into changed behavior instead of sporadic diplomacy.
ASEAN’s Mechanisms and the Deadlock
This Cambodia-Thailand war is a serious test of ASEAN’s institutional strength. ASEAN’s order is founded on norms of non-interference, sovereign equality, and consensus decision-making. These norms support solidarity, but they limit intense forms of intervention when member states are in disagreement or in profound conflict. On July 27, 2025, the statement of ASEAN Foreign Ministers called for restraint and referred to the ASEAN Charter and the Treaty of Amity and Cooperation as the basis of disagreement resolution.
However, the statement did not include mechanisms for enforcement or graduated sanctions. Even in this cycle ASEAN’s role was essentially facilitative, providing meetings, issuing statements, and supporting the Malaysian-led observer mission. There was no ASEAN-imposed peace force, no neutral arbiter sanctioned by both parties. This reveals the structural limitation of ASEAN in the face of interstate armed conflict. Finally, the conflict illustrates ASEAN’s limits in its preventive capacities. Discussion had been done under the Joint Border Committee (JBC) and General Border Committee (GBC), i.e., June 14-15, 2025, and produced nothing substantial. By the time ASEAN intervened in late July, the conflict had already gone beyond military language. Essentially, ASEAN’s mechanisms were reactive rather than proactive, and that is a discredit to its role as a regional conflict manager.
Rethinking ASEAN’s Role and Strategic Recommendations
For ASEAN to stay relevant in dealing with intra-regional boundary disputes without forsaking its fundamental norms of sovereignty and non-interference, then it has to rethink its structure and strategy. Firstly, the consensus-based decision-making while maintaining state equality has turned into a bottleneck. Referring to Barry Buzan and Ole Wæver’s framework of regional security, we notice that regional organizations have to balance normative commitments with incremental institutional empowerment. ASEAN has the option of a two-stage process under which willing member states consent to a more intense peer-review or arbitral process for border conflicts.
Second, invoking John Paul Lederach’s Conflict Transformation Theory, the region requires more than observer missions and ceasefires. It requires trust infrastructure and local networks and cross-border links. ASEAN could facilitate shared community forums for Cambodian and Thai border communities, cross-border de-mining coordination, and joint patrol training under neutral facilitation. These actions over time generate ownership and reduce relapse risk.
Third, ASEAN observer deployment has to be better improved. The current monitoring is symbolic with a soft mandate. A more appropriate design would establish an ASEAN Border Peace Monitoring Cell on a standing basis staffed by member country military attaches, submitting periodic reports to the ASEAN Secretariat and underscored for high-level review if there is a breach. This would be appropriate under Robert Keohane’s concept of institutionalized volunteering, where power is delegated by states to mitigate coordination failures.
Fourth, ASEAN can promote the concept of “conditional cooperation,” where peaceful resolution of border disputes becomes linked to engagement in connectivity and regional economic initiatives. For example, the Thailand-Cambodia border corridor is pivotal to the East-West Economic Corridor. By establishing non-settlement as an economic loss, ASEAN can raise the political costs for the member states and produce incentives for compliance.
Fifthly, in balancing action and non-interference, ASEAN may adopt a protocol-based approach. Where two members are in dispute, they may opt into a “Border Conflict Protocol” within ASEAN, agreeing to arbitration, observer missions, and graduated implementation. This would be voluntary, respecting sovereignty, but once signed, subject to peer pressure and monitoring.
In sum, ASEAN must evolve from a convenor of conversation to the guarantor of conflict management. The Cambodian-Thai conflict is an eye-opener. Without adaptation, ASEAN is at risk of marginalization and its dominance in Southeast Asian security architecture being destroyed.
Conclusion
The Cambodia–Thailand border conflict has once again exposed the weakness of regional diplomacy in Southeast Asia. Even after six decades of institutional evolution, ASEAN continues to react to conflicts in the same old language of consensus, restraint, and dialogue. The July 2025 crisis revealed how ASEAN’s original principle of non-interference, celebrated earlier as a protector of regional stability, has today become an obstacle to collective security.
It is the duality of sovereignty that continues to paralyze the organization whenever its members confront each other with guns. The partial success of the Malaysian-led mediation and subsequent August 2025 ceasefire attest that ASEAN’s convening power still matters. Power to convene, however, is distinct from power to solve. Without early warning, accountability, or enforcement, ASEAN remains a mere observer of peace and not its builder. The Cambodia-Thailand border may become quiet for now, but silence is not the same as reconciliation. A more accurate assessment must make ASEAN reflect on its own self-image. It must ask itself if the beloved “ASEAN Way” of national sensitivity still rings in tune with the collective security concerns of ASEAN peoples.
Can a regional institution genuinely pretend to centrality while it remains unable to prevent fighting among its own membership? It is not merely a bilateral strain. It is a mirror held against the weaknesses of Southeast Asian regionalism itself. If ASEAN cannot turn its ethos into effective tools of peace, then the dream of “One Vision, One Identity, One Community” will forever be an unfinished dream. The line can be redrawn, but can ASEAN redraw its own courage?
