Wars between Southeast Asian states are supposed to belong to another era. When they reappear, they do so quietly, fragmentarily, often misread as “border incidents” or residual nationalism rather than as symptoms of deeper regional stress. The renewed conflict between Cambodia and Thailand, which escalated into a second and longer phase of open warfare in 2025, disrupts that comforting assumption. It reveals not only the fragility of bilateral mechanisms, but also the limits of ASEAN’s conflict-management architecture and the growing willingness—once again—to use force in a region that prides itself on restraint.
In this interview that I had the opportunity to conduct with Him Rotha —deputy director of the Cambodian Center for Regional Studies— the academic offers an unusual reading, both from the field and from a strategic perspective, of the conflict. His analysis moves beyond the immediate military dynamics to unpack the domestic political pressures in Thailand, the role of local border actors, and the broader implications for ASEAN centrality and the Indo-Pacific security order. Particularly striking is his account of how mediation has unfolded across multiple layers: ASEAN’s constrained mechanisms, China’s low-profile shuttle diplomacy, and the United States’ personalized, high-leverage intervention under the Trump administration.
What emerges is not merely a bilateral dispute, but a case study in contemporary Asian geopolitics: nationalism under domestic strain, small-state insecurity in an era of eroding norms, and great-power involvement that oscillates between stabilization and strategic signaling. At stake is more than the Cambodia–Thailand border. The conflict raises a harder question for Southeast Asia and beyond: whether the region’s long-cherished principles of non-use of force and multilateral management can still hold in an increasingly militarized Indo-Pacific.
1- How would you describe the current dynamics on the ground in the Cambodia–Thailand conflict, and what distinguishes this phase from previous episodes of tension?
The second round of the war between Cambodia and Thailand went on longer than the first phase. It lasted 21 days with multiple fronts, from the longstanding disputed zones around Preah Vihear Temple in the north of Cambodia to westward around the populated area of Poipet and went down to Koh Kong, a coastal province by the Gulf of Thailand. Different from the first round, the Thai Military pronounced the second phase of war with the aim to “cripple Cambodia’s military capability,” an objective that is so rare and almost non-existent in the 21st Century in Southeast Asia. The first round of war ended with a ceasefire the decisive mediation by the US President Donald Trump’s phone calls to both Cambodian and Thai leaders. Yet, in the second phase, although with repeated mediation by ASEAN, the US, and China’s shuttle diplomacy, the conflict was frozen with a ceasefire agreement termed during Defense Ministerial level meeting, called General Border Committee (GBC) between Cambodia and Time, lasted for four days, ended on 27 December 2025.
2- What are the main local and domestic political factors in both Cambodia and Thailand that are shaping the evolution of the conflict today?
Indeed, both domestic political landscapes in Cambodia and Thailand contributed to this on-going conflict between the two Kingdoms. The rise of nationalistic sentiments and longstanding cultural disputes within these two countries, in one way or another, have posed a big challenge towards reconciliation and restoration of diplomatic relations of the two countries.
Nevertheless, it is undeniable that the situation of domestic politics in Thailand has been highly factored in the evolution of this conflict. Thailand has been undergone some political transformation since the coup in 2014 and the election in 2023. In 2023, a civilian government was formed with a grand compromise with the Thai Military, a faction that is considered as the ruling establishment in Thailand. However, the Thai Military is observed to be under a lot of pressures domestically with the growing calls for reforms by several domestic groups in the country. Thus, the issue of nationalistic sentiment emerges and the border issues with Cambodia, including the disputed and overlapped claims in the maritime sphere and some unresolved temples areas were brought to the discussion again within the Thai political discourses.
The current conflict between Cambodia and Thailand was intensified after a brief clash back in May 2025, resulted one Cambodian soldier died. In June, the tensions between the two countries continued back and forth, including the leaked phone call between Cambodian top leader, Hun Sen and the then-Thai Prime Minister, Paetongtarn Shinawatra. The relations between Cambodia and Thailand continued to decline to the point that the war broke out in late July 2025.
3- To what extent do border communities and local actors influence escalation or restraint in this dispute?
Indeed, local actors along the border did in some shapes and forms contributing to the escalation of this dispute. One Thai prominent diplomat, Tej Bunnag once said:
Thai–Cambodian relations were out of the control of people at head-quarters. On both sides of the border, issues were generated by local people with power, influence, and interests. When they reach dangerous levels, these issues become political issues in the national capitals.
“Local people with power, influence, and interests” here may be referred to the Thai military regional commands that are in charge of Thai-Cambodian border affairs. There are some rumors that said that there are some illicit business interests along both ends of the border and conflict of interests have been erupted over the time. However, during this time, these issues are politicized and inflamed bigger that led to have such war between the two countries.
Nevertheless, it is undeniable that there are some actors, especially business groups along the border also wish the conflict to stop by advocating for the re-opening of the border. With the hyper-politicization and nationalism along both ends of the border, these voices are marginalized.
4- How does the current Cambodia–Thailand conflict affect regional stability in Southeast Asia, particularly within ASEAN?
The current conflict between Cambodia and Thailand is an alarming issue for the peace and stability in Southeast Asia, and I can even argue that it indeed poses a huge challenge for the geopolitical and geoeconomic landscape for the whole Indo-Pacific region. For Southeast Asia, this conflict adds another stress along with the ongoing situation in the South China Sea and the situation in Myanmar, where there is an ongoing civil war as an aftermath of the military coup back in 2021. This conflict, if not properly managed, could be a precedent of increasing eagerness and willingness of using forces to settle inter-state disputes, contrasting to the principle of non-use of forces in dispute settlement that is part of the rules-based international order in the 21st Century.
5- Do you see this dispute as a challenge to ASEAN’s principle of conflict management and its claim to regional centrality?
Indeed, it is a challenge towards ASEAN and its so-called centrality. Small states, like Cambodia, with limited military capabilities would mostly rely on the principle of international laws and regional mechanism to settle disputes. It should be acknowledged that ASEAN with the spearheaded by Malaysia as the group chair in 2025 has tried its best to manage the conflict from spreading further. Malaysia has dispatched observers and mobilized ASEAN nations to observe the conflict under the framework of ASEAN Observer Team (AOT). The efforts to “manage” the conflict is commendable, but it is not enough to stop and prevent another war owing to the lack of participation from other regional states. With the ineffective international and regional mechanism, it would push small states in the region to resort with other exhausted means to safeguard their sovereignties and territorial integrity.
6- What implications does this conflict have for the broader Indo-Pacific security order?
The implication of this conflict is the growing eagerness and willingness of using military forces to settle inter-state disputes. Like what I mention above, smaller states would resort to any means to safeguard their sovereignties. Indo-Pacific security order is already under pressured with the rising of tensions along the disputed zones. Thus, it is needed to enhance the concept of multilateralism and the principle of international laws in the region or else, the region will be under a complex network of security alliances and armed races, which are prone to armed escalations, affecting regional peace, stability and prosperity.
7- How have China and the United States approached mediation or diplomatic engagement in this conflict so far?
China and the United States have respective strategic interests in approaching this conflict. For China, it is well known that Southeast Asia, especially Mainland Southeast Asia, is a close neighbor. Cambodia and Thailand are both close friends to China. Therefore, one way or another, China would like to see these two countries are at peace with one another; on the one hand, for the sake of peace and stability in Mainland Southeast Asia, and on another, for enhancing China’s interests be it economic supply chains or strategic interests in dealing with ASEAN owing to the fact that China has many things to deal with in Southeast Asia, from the conclusion of the Code of Conduct in the South China Sea to strengthening its formidable presences in the region. China has managed this conflict through its low-profile way and shuttle diplomacy.
For the US, on the other hand, Thailand is its treaty ally, just one of the four allies in Asia. Cambodia is a country of interests to the US as well. The US, under the Trump Administration, are in the bid to strengthen its strategic presence in the Indo-Pacific, thus, it is in its interests to mediate in this conflict.
It should be noted that in the war between Cambodia and Thailand, both countries have used Chinese weapons in some shapes and forms. Thailand even went further by using the US-made F-16 fighter jets to bomb on some targets that they deem to harm their military presences in the conflict zones, which spillover to some civilian infrastructures.
8- What are the key differences between Beijing’s and Washington’s mediation strategies and interests in this case?
Currently, the key difference is that Beijing has opted for low-profile and shuttle diplomacy to engage in mediation between Cambodia and Thailand. Low-profile to the sense that China wants to have a quiet role and under the radar basis.
The US, on the other hand, President Trump played a crucial role by himself through his phone call diplomacy towards both Cambodian and Thai leaders. The US President utilized trade tariff as a leverage to pressure both Cambodia and Thailand to stop the war back in the first round of the war in July. He went on to witness the Peace Accord signed by Prime Minister Hun Manet of Cambodia and the Thai Prime Minister, Anutin Charnvirakul back in October in Malaysia. However, the US Administration and Washington foreign policy circle also utilize this opportunity to enhance its presence in Southeast Asia, a region with high influence of China. The US has also worked with ASEAN and pledges to provide satellite for the AOT team to verify and monitor the ceasefire arrangement under the framework of Peace Accord signed in October.
9- Is there a risk that the Cambodia–Thailand conflict could become another arena for US–China strategic competition?
This conflict has become a geopolitical issue, owing to the involvement of other external actors. Not only the US and China engage in this conflict. Japan has played a quiet and unique role, generating with its investors’ interests in both sides of the border. The EU, France, and the UK have become more active in the second phase of the conflict with the pledges of support towards the post-conflict recovery and humanitarian assistances towards around 1 million displaced persons in both Cambodia and Thailand.
For the arena of the US-China strategic competition, this conflict has only generated as a diplomatic competition at the moment to support the peaceful end of conflict. The US had a heads up with the Peace Deal, witnessed by President Trump. However, for the second phase of the war, China has shown increasing efforts to help mediate the conflict by publicizing its shuttle diplomacy of its Foreign Ministry’s Special Envoy and is in the process of organizing the mediation talk in China in late December.
Nevertheless, it should be pointed out that the important roles of the both US and China and other friendly countries which have shown proactiveness to help stop the fighting, support non-use of forces to settle disputes, and advocate for peaceful resolutions between Cambodia and Thailand.
10- From Cambodia’s perspective, what type of mediation or regional framework would be most conducive to a durable and peaceful resolution?
The most conducive to a durable and peaceful resolution is a type of mediation that involves with multilateral actors and also with acceptable mechanisms in order to let both conflicted parties to accept into a durable peace. Cambodia’s position is to seek for peace and to ensure the ceasefire to hold, it is needed to have a credible and effective observer or even transforming observers into peacekeeping forces. If this occurs, it would set a good example for ASEAN and the international community to manage state-to-state conflict in the contemporary era.
Other than that, I think it should be time to discuss about the post-conflict recovery. Post-Conflict Recovery would cover two main important issues; namely, (1) humanitarian and economic recovery for displaced persons and civilian facilities along the affected zones; and (2) post-conflict diplomatic restoration between Cambodia and Thailand. For the first point, external actors, could jump in to facilitate the support for civilians. It is part of the human security as after all, human lives shall be protected from any uncivilized intimidation. For the second point, friends to both Cambodia and Thailand could provide a conducive good office to restore the relations between the two Kingdoms. A normalized relations between Cambodia and Thailand is in the best interests of Southeast Asia and the Indo-Pacific. The restoration of relations between Cambodia and Thailand does not only contribute to the betterment of inter-dependence of the Cambodian and Thai people along the border, but also a connectivity restoration for ASEAN and beyond.
Abogado, Mágister, y Doctor en Relaciones Internacionales (CONICET).
