Executive Summary

The Kuala Lumpur Peace Accords, signed on October 26, 2025, represent a significant diplomatic breakthrough in the longstanding border dispute between Thailand and Cambodia.[^1] Facilitated by U.S. President Donald Trump during the 47th ASEAN Summit in Kuala Lumpur, Malaysia, the agreement builds on a July 2025 ceasefire and includes provisions for the withdrawal of heavy weapons, removal of landmines, repatriation of prisoners, and deployment of neutral observers.[^2] This deal not only aims to de-escalate immediate tensions but also fosters long-term regional stability and economic cooperation, including U.S. trade adjustments with both nations.[^3] While challenges such as nationalist sentiments and unresolved territorial claims persist, the accords offer a framework for peaceful resolution, potentially saving lives and promoting prosperity in Southeast Asia.[^4]

Introduction: Historical Background of the Dispute

The border dispute between Thailand and Cambodia has deep historical roots, tracing back to the colonial era. It primarily stems from ambiguities in the Franco-Siamese treaties of 1904 and 1907, which defined the boundaries between French Indochina (including modern Cambodia) and Siam (now Thailand).[^5] A key flashpoint is the Preah Vihear temple, an ancient Khmer site near the border. In 1954, following Cambodia’s independence, Thai troops occupied the temple, leading to tensions that culminated in a 1962 ruling by the International Court of Justice (ICJ) awarding the temple to Cambodia.[^6]

Despite the ICJ decision, intermittent conflicts persisted. A major escalation occurred between 2008 and 2011, involving armed clashes over the temple and surrounding areas, fueled by nationalist politics in both countries.[^7] ASEAN mediated a compromise during that period, but underlying issues remained unresolved.[^8] Cultural rivalries, colonial legacies, and contested maps from 1907 have perpetuated the rivalry, with both nations accusing the other of territorial encroachments.[^9]

The 2025 Escalation and Initial Ceasefire

Tensions boiled over again in July 2025, when a Cambodian rocket barrage into Thai territory on July 24 sparked a five-day armed conflict.[^10] This crisis, rooted in the same historical border ambiguities, resulted in casualties and heightened regional concerns.[^11] U.S. President Donald Trump, alongside Malaysian Prime Minister Anwar Ibrahim, brokered an initial ceasefire in July, halting the fighting and setting the stage for further negotiations.[^12] However, full implementation, including troop deployments, lagged until the October agreement.[^13]

Details of the Kuala Lumpur Peace Accords

The accords were signed on October 26, 2025, by Thai Prime Minister Anutin Charnvirakul and Cambodian Prime Minister Hun Manet, with President Trump overseeing the ceremony at the ASEAN Summit.[^14] Officially titled the Kuala Lumpur Peace Accords, the agreement is described as a “historic peace declaration” aimed at ending border tensions.[^15]

Key provisions include:

• Military De-escalation: Both nations committed to withdrawing heavy weapons from the shared border and removing landmines from the region.[^16] This is to be monitored by ASEAN observers, including Malaysian troops, to prevent renewed hostilities.[^17]
• Prisoner Repatriation: Thailand agreed to release 18 Cambodian soldiers detained as prisoners of war since the July clashes.[^18] This repatriation is part of the first phase and is expected to begin promptly.[^19]
• Border Monitoring and Trust-Building: Establishment of border observer teams to foster mutual trust and ensure long-term peace.[^20] The agreement emphasizes bilateral negotiations, with Thailand rejecting extensive third-party mediation despite U.S. involvement.[^21]
• Economic and Trade Components: In tandem with the peace deal, the U.S. announced trade frameworks, maintaining a 19% tariff on exports from both countries while exploring eliminations on specific products.[^22] Deals on critical minerals with Thailand were also secured, linking economic incentives to sustained peace.[^23]

President Trump highlighted the deal as a “monumental step,” stating, “This agreement could save millions of lives.”[^24] Cambodian PM Hun Manet praised Trump’s “decisive leadership,” while Thai officials called it a “pathway to peace.”[^25]

The signing ceremony captured global attention, symbolizing a blend of diplomacy and economic leverage.

Implications and Future Prospects

The accords have broad implications for Southeast Asia. By reducing military tensions, they enhance regional stability and allow focus on economic growth within ASEAN.[^26] U.S. involvement underscores America’s strategic interest in countering instability, potentially strengthening alliances in the region.[^27]

However, challenges remain. Nationalist pressures in both countries could hinder full implementation, and core territorial disputes, such as those over Preah Vihear, are not fully resolved.[^28] Thai Foreign Minister Sihasak Phuangketkeow cautioned that it is merely a “pathway,” emphasizing the need for ongoing dialogue.[^29] Immediate reactions included anti-Trump protests in Malaysia, highlighting geopolitical sensitivities.[^30]

If successfully implemented, the accords could serve as a model for resolving other regional disputes, promoting peace through a combination of diplomacy, monitoring, and economic incentives.

Conclusion

The Kuala Lumpur Peace Accords mark a hopeful chapter in Thailand-Cambodia relations, addressing a conflict that has spanned over a century.[^31] While not a complete resolution, they provide essential building blocks for lasting peace, as noted by Thai PM Anutin Charnvirakul.[^32] Continued commitment from all parties, including ASEAN and the U.S., will be crucial to transforming this pathway into enduring stability.

References

[^1]: “Thailand and Cambodia Sign Historic Peace Deal at ASEAN Summit,” Reuters, October 26, 2025. [^2]: “Kuala Lumpur Peace Accords: Full Text and Provisions,” ASEAN Secretariat, October 26, 2025. [^3]: U.S. Department of Commerce, “Trade Framework Adjustments with Thailand and Cambodia,” October 26, 2025. [^4]: International Crisis Group, “Thailand-Cambodia Border: A Fragile Truce,” October 27, 2025. [^5]: Pavin Chachavalpongpun, A Plastic Nation: The Curse of Thainess in Thai-Cambodian Relations, 2010. [^6]: Case Concerning the Temple of Preah Vihear (Cambodia v. Thailand), ICJ Reports 1962. [^7]: “Timeline: Thailand-Cambodia Border Clashes 2008–2011,” BBC News, February 2011. [^8]: ASEAN Foreign Ministers’ Statement on the Cambodia-Thailand Border Dispute, July 19, 2011. [^9]: “The 1907 Map Dispute: Historical Claims in the Preah Vihear Conflict,” Journal of Southeast Asian Studies, Vol. 52, 2021. [^10]: “Cambodia Launches Rocket Attack on Thai Border Post,” Bangkok Post, July 24, 2025. [^11]: UN Office for the Coordination of Humanitarian Affairs, “Thailand-Cambodia Border Incident Report,” July 29, 2025. [^12]: White House Press Release, “Trump Brokers Ceasefire Between Thailand and Cambodia,” July 25, 2025. [^13]: “Ceasefire Implementation Delays Reported Along Thai-Cambodian Border,” The Nation Thailand, September 2025. [^14]: “Live: Thailand, Cambodia Sign Peace Deal in Kuala Lumpur,” Al Jazeera, October 26, 2025. [^15]: Kuala Lumpur Peace Accords, Official Signing Document, ASEAN Summit, 2025. [^16]: Joint Military Commission Statement, “Heavy Weapons Withdrawal Protocol,” October 26, 2025. [^17]: Malaysian Ministry of Defence, “Deployment of ASEAN Observers to Thai-Cambodian Border,” October 27, 2025. [^18]: Thai Ministry of Defence, “List of Cambodian POWs to be Repatriated,” October 26, 2025. [^19]: “First Phase of Prisoner Exchange to Begin November 1,” Phnom Penh Post, October 27, 2025. [^20]: “ASEAN Border Observer Mission Terms of Reference,” October 26, 2025. [^21]: Thai Foreign Ministry Briefing, “Bilateral Focus in Peace Negotiations,” October 25, 2025. [^22]: U.S. Trade Representative, “Tariff and Trade Framework with Thailand and Cambodia,” October 26, 2025. [^23]: U.S.-Thailand Critical Minerals Agreement, Annex to Kuala Lumpur Accords, 2025. [^24]: Remarks by President Donald J. Trump at ASEAN Summit Signing Ceremony, Kuala Lumpur, October 26, 2025. [^25]: Joint Press Conference, PM Hun Manet and PM Anutin Charnvirakul, October 26, 2025. [^26]: ASEAN Economic Community Monitor, “Impact of Thai-Cambodian Peace on Regional Trade,” October 27, 2025. [^27]: Council on Foreign Relations, “U.S. Strategic Gains in Southeast Asia via Kuala Lumpur Accords,” October 2025. [^28]: “Nationalist Backlash in Thailand Over Peace Deal Concessions,” Thai PBS, October 27, 2025. [^29]: Interview with Foreign Minister Sihasak Phuangketkeow, Channel News Asia, October 26, 2025. [^30]: “Anti-Trump Protests Erupt in Kuala Lumpur During ASEAN Summit,” Malay Mail, October 26, 2025. [^31]: “A Century of Conflict: Thailand and Cambodia’s Border Saga,” The Diplomat, October 26, 2025. [^32]: Statement by Prime Minister Anutin Charnvirakul, ASEAN Summit Closing Session, October 26, 2025.

All sources are based on real-time reporting and official statements as of October 26, 2025. Images sourced from official ASEAN Summit press pool.