The clash between Cambodia and Thailand, in July 2025, was one of the deadliest confrontations of the two states’ contemporary history. The clash took more than 38 lives, displaced hundreds of thousands of civilians, suspended over 500 schools, and inflicted infrastructural damage to countless homes, hospitals, and historical and religious sites. These included irreplaceable heritage monuments such as Ta Muen Thom, Ta Muen Toch, Ta Krabei, and the Preah Vihear Temple, which is a UNESCO World Heritage site.
The Root of the Conflict
While the military clash between Cambodia and Thailand broke out on 24 July 2025, the cause of the confrontation was rooted in two main issues: the conflicting border maps interpretations and the incident on 28 May 2025.
Back when Cambodia was still a part of the French colonial state in Indochina, along with Vietnam and Laos, in the early 20th century, both France and Siam (Thailand’s predecessor) signed the 1907 Franco-Siamese Treaty. In the treaty, Siam would return Siem Reap, Battambang, and Banteay Meanchey back to Cambodia, while France agreed to withdraw from Siam’s Trat and Dan Sai. Using the agreed 1:200, 000 scale, both France and Siam were able to demarcate the borderline between Siam and Cambodia. The map was internationally recognized, most notably by the International Court of Justice (ICJ) in its 1962 ruling on the Preah Vihear Temple.
Differently, Thailand utilized its 1:50, 000 scale map as Bangkok claimed that the scale provided more detailed and precise information regarding the boundary demarcation. The ICJ ruled in favor of Cambodia again in 2013 through the utilization of the map that was used in the 1962 ruling. Therefore, although the 1:50, 000 scale map’s precision was claimed by Thailand, it was not accepted by the ICJ in the 2013 ruling. Hence, the differences between Thailand and Cambodia in utilizing their map when discussing the border issue remain one of the variables that led to the fragile peace on the border conflict.
In addition, the 2025 Cambodia – Thailand clash heated up since May 2025 when a Cambodian soldier was killed during a clash, with the cause still a controversy as both sides have different claims on who initiated the first fire. What followed in June was the massive boycott in which Thailand shut down its border for trade with Cambodia while Phnom Penh opted out of Thai internet service, electricity, and fuel supplies. In mid-July 2025, the Thai soldiers stepped on a landmine near the disputed area, which resulted in the recall of Ambassadors from both sides and the deterioration of relations to the lowest level. The military confrontation broke out on 24 July, near the Ta Moan Thom temple, until 28 July 2025.
The outbreak of heavy military confrontation between the Royal Cambodian Army and the Royal Thai Army lasted for five days and halted with a ceasefire that was reached in Malaysia. This ceasefire agreement was brokered by U.S. President Donald Trump and the Malaysian Prime Minister Anwar Ibrahim, the current rotating chair of ASEAN, with the support of the People’s Republic of China. In the truce, Cambodia and Thailand both agreed to an immediate and unconditional ceasefire, meetings between the two states’ regional commanders, and conducting the General Border Committee (GBC) – a body that is led by the Defense Ministries of both countries with the primary focus of addressing the military-to-military mechanism. All these agreements were made with the focus on de-escalating the tension and bringing the fighting to an end.
Potential Key Takeaways
Given both states’ proximity with a shared land border stretching over 800 kilometers, there are significant lessons that Phnom Penh and Bangkok should consider in the aftermath of the recent border clash.
Firstly, this confrontation presented a new type of warfare and intensity for both Cambodia and Thailand that was different from the past. In the 2008 border clash, both Phnom Penh and Bangkok utilized small conventional arms, rocket-propelled grenades (RPGs), and artillery without the use of air power or large-scale heavy weaponry. Throughout the clash in 2025, various military strategies were employed, from establishing aerial superiority, implementing information warfare, and gathering intelligence for the purpose of espionage. In addition, while Cambodia has depended heavily on BM-21 systems and rocket launchers to deliver heavy artillery, Thailand has deployed its F-16 and Gripen fighter jets to target Cambodia’s military sites with missile strikes and used cluster munitions, a type of explosive that is banned by the Convention on Cluster Munitions (CCM). The artillery from Cambodia’s rocket launchers is not guided and relies on the high concentrations of rockets hitting a general area to damage the target. Contrastingly, Thailand’s F-16 and Gripen fighter jets are equipped with precision and guided technology, enabling the Thai military to spot and effectively hit the intended target once identified.
Thailand’s superior air capabilities have fundamentally changed both states’ modern confrontations compared to decades ago. This shortcoming from the Khmer side also enabled Bangkok to engage in drone strategies, where the Royal Thai army sent in spy and armed drones that can gather information for precision strikes and can be equipped with artillery to blow up major Cambodian weapon depots. Moreover, the fight was not solely limited to the northern border area, but this time also extended towards the western border in Cambodia’s Pursat province, where Thailand also deployed its naval forces to standby as a contingency.
Furthermore, human intelligence operations were also used during the clash, where the Cambodian military detained several individuals involved in espionage. These individuals were found to be equipped with technology to gather sensitive information on critical locations such as military bases, weapon depots, and civilian areas.
The information battle has also played a significant role, with certain media outlets contributing to the spread of propaganda, false, unverified, and rumor-driven information. This resulted in confusion among viewers regarding critical aspects of the confrontation, such as the origin of the first shot and key events during the operation.
Secondly, the clash between Cambodia and Thailand showcased ASEAN’s relevance in regional peacemaking, despite its tardy response. The ceasefire agreement revealed that ASEAN offered a vital platform for mediation when bilateral mechanisms failed to do so. Bangkok and Phnom Penh have been engaging in a one-on-one dialogue through the Joint Border Commission (JBC), a mechanism that focuses on technical and legal issues regarding the shared border. This mechanism was established under the 2000 Memorandum of Understanding (MoU) between the two countries with the aim of providing a structural framework for the peaceful demarcation of their shared border. Despite having such a platform since 2000, the issues regarding the border demarcation could not be fully resolved and facilitated impasse.
The intervention from ASEAN underscores that the grouping’s centrality is vital when bilateral mechanisms break down. ASEAN, as a neutral and independent platform, enables dialogue and prevents disputes from escalating into an all-out “might makes right” confrontation. ASEAN’s multilateral framework grants an effective path to resolve the prolonged border issue and ensure that the solutions are grounded in international law rather than the dominance of national interests.
The Foreseeable Challenges
While the truce between Cambodia and Thailand has halted the fighting, the fragility of the ceasefire should not be overlooked. Despite Cambodia’s calls for a ceasefire at the start of the conflict, the eventual ceasefire agreement was able to come through only due to the continued encouragement from ASEAN to mediate the issue and the involvement of external players, such as the United States. The U.S. President threatened not to engage in trade deals with both states if the fight continues – an economic pressure towards the two countries, which have strong trade volume with Washington. It is anyone’s guess whether the truce will hold after the U.S. leader finalizes the trade deal in early August 2025.
Moreover, the agreement posited no specific timeline nor specific means to resolve the long-standing border dispute between Cambodia and Thailand. The truce was only made with the goals of ceasing hostilities and ensuring the two sides remain in peace talks with each other. Although this is adequate in the short term, the two sides could engage in another confrontation in the future if the multilateral and neutral mechanism is ignored, due to national interest, and if the GBC fails to bring about a solution to the issues, like the JBC did.
The Bumpy Road Ahead
Despite the clash lasting for five days, the restoration of trust across all levels – both between the two governments and between their citizens – appears bumpy. The prevailing sentiment of distrust and heightened nationalism ought to be significant challenges that can obstruct both the Cambodian and the Thai cooperation down the road. In spite of the possible resumption of government-to-government collaboration in areas such as trade and investment, rebuilding people-to-people relations may prove more difficult. Without the government incentive as a head start, the light at the end of the tunnel remains dim.
Moreover, with the assumption that the 28 July 2025 ceasefire agreement would still be in place, both Cambodia and Thailand will have to deal with internal obstacles that emerged in the post-conflict environment such as infrastructural reconstruction, defense refurbishment, and the citizens’ psychological reconciliation – all of which would take years to adjust and accomplish under the new paradigm.
Bunly Ek is a Young Leader for the Pacific Forum and a Research Fellow at the Cambodian Center for Regional Studies (CCRS). He is the 2022 Global Korea Scholarship (GKS) graduate at Yonsei University in the Republic of Korea, majoring in International Security & Foreign Policy in East Asia. His research interest focuses on ASEAN – U.S. relations and Northeast Asia security dynamics. Email: [email protected]
The views expressed are the author’s own and do not reflect the editorial direction.
Photo: Hun Manet (left), Anwar Ibrahim (middle), and Phumtham Wechayachai (right) shook hands during their meeting in Malaysia || Source: Hun Manet Facebook Page