Introduction:

The 2025 escalation of the Thailand-Cambodia conflict has once again drawn attention to the Temple of Preah Vihear, which lies at the centre of the conflict. Preah Vihear, a UNESCO-listed world heritage site, sits at the border between the two countries. While landmine incidents and troop movements triggered the current violence, the roots of the confrontation lie deep in the question of territorial ambiguities surrounding the temple. The ICJ in 1962 ruled that the temple itself is under Cambodian territory, and the surrounding areas remain contested lands. Moreover, the absence of clearly demarcated boundaries between the two countries has allowed the competing claims to persist even to this date.  The history of the two countries is complex, including instances of colonial control, cultural overlaps, and genocidal regimes like the Khmer Rouge. 

The colonial borders that were drawn did not respect the cultural sensitivity of historical sites such as the Temple of Preah Vihear. Thus, the religious site, which was supposed to bring cultures and people together, today has become the focal point of cross-border firings, trade embargoes, and even airstrikes, displacing people in the thousands and costing innocent lives.

The conflict lays bare the limitations of the rulings of international bodies such as the ICJ and the inability to build consensus within Southeast Asia through multilateral bodies like ASEAN. A conflict that dates back to the 1900s continues to plague the region. The recurring conflict has resulted in severe economic and humanitarian implications, the ripple effects of which are felt throughout the region. The strategic consequences of this conflict are being borne by external stakeholders like India, whose connectivity and outreach projects under the Act East ambitions are being hampered.

Timeline:

• 9th-15th Century: Southeast Asia was under the dominance of the Khmer Empire, which extended over parts of modern-day Thailand, Laos, and Vietnam.

• 15th Century: The Khmer Empire was in decline and was rivalled by the Siamese Kingdom, which sacked the Khmer capital of Angkor.

• Late 16th Century: Cambodia found itself surrounded by two growing powers, Siam and Vietnam.

• 19th Century: The instability in the region persisted until the wave of French colonialism, when Cambodia became a French protectorate, guaranteeing its security.

• However, since Thailand was never colonized, it was able to economically outperform Cambodia. Moreover, Cambodia lagged because of its tumultuous history with the involvement of the Vietnam War and the genocidal Khmer Rouge.

• 1907: Because of the colonial dynamics, the Franco-Siamese Treaty was signed, which defined much of the borders between Cambodia, Laos, and Thailand. Under this treaty, the Temple of Preah Vihear was returned to Cambodia, a move which attracted Thailand’s criticism.

• During WWII, Thailand aligned itself with Japan and was able to reclaim much of its lost territory, including the Temple of Preah Vihear. Nevertheless, Thailand returned the temple to Cambodia in a bid to join the UN.

• 1953: After the Cambodian independence in 1953, Thailand sent troops to reoccupy the Temple of Preah Vihear.

• 1959: Cambodia takes the dispute to the International Court of Justice (ICJ).

• 1962: The ICJ ruled in Cambodia’s favour, granting it control over the Temple, but the territorial status of the surrounding lands was ambiguous. It is due to this ambiguity that the competing claims persist even today.

• 2008: UNESCO’s registration of the Temple of Preah Vihear as a World Heritage Site revived the tensions between the two countries.

• 2008-2011: Several instances of border clashes left at least 20 dead and thousands displaced.

• 2013: After the case was appealed in the ICJ by Cambodia, the court asked all troops to be withdrawn from the region and, in 2013, ruled that the temple and the territory in its immediate vicinity came under Cambodian jurisdiction.

2025 Escalations (May-December):

• May 28: A skirmish near the temple complex left a Cambodian soldier dead. Who initiated the violence is debated, but the buck-passing triggered another wave of violence in the region. During which, Thai goods were banned in Cambodia, and the borders were closed, along with restrictions being imposed on the internet and electricity.

• July 23: In the Ubon Ratchathani province of Thailand, a Thai patrol triggered a land mine, which injured 5 soldiers. Thailand accused Cambodia of placing new landmines on the border.

• July 24: Fighting broke out near the Ta Muen Thom Temple. The violence expanded to 12 different border locations.

• July 28: Thailand & Cambodia agreed upon an “immediate & unconditional ceasefire.”

• November 11: Another landmine explosion injured Thai troops, following which Thailand declared that the ceasefire was no longer operative.

• December 8: Thailand launched a series of airstrikes targeting Cambodian military facilities

• December 10: The fighting expanded to drone attacks, intensified air strikes, and rocket fire, along with ground clashes across the Thai-Cambodian border.

As of December 2025, the Thai-Cambodian bilateral relations remain at their lowest in recent years. The imposition of curfews in the border provinces has restricted the transportation and exports of fuel and arms. It has forced the civilians in the region to shift to displacement shelters. The diplomatic engagements remain limited as both sides reject external mediation and accuse each other of violating the ceasefire first.

Strategic Implications for State & Non-State Actors:

The 2025 escalations have adversely impacted the Thailand-Cambodia bilateral trade, which was valued at $3.169 billion in 2023, making Thailand Cambodia’s 4th largest trading partner. For businesses on both sides, this spells supply chain disruptions, a stark increase in logistics and insurance costs, along with loss of revenue from Tourism, which has been a major source of revenue for both countries. Specifically, the manufacturing and agricultural exports are the worst hit. The road and border closures have affected the fuel transit routes, causing a concerning energy insecurity. 

Moreover, Thailand has stopped the export of fuel and arms to Laos, as there remains a concern that these resources were being diverted towards helping the Cambodian troops. The defence spokesman of Thailand, Surasant Kongsiri, said that: “We’re imposing this measure primarily to stop the use of Thai-registered vessels to transport fuel and other possible armaments to support the Cambodian troops.” Further, the constant imposition and subsequent violations of the ceasefires have undermined investor confidence, as a credible dispute-resolution framework remains absent. The infrastructure projects near the border, consisting of road projects, construction of SEZs, and logistics hubs, have stalled with no clear date being specified for when they might resume.

India’s Strategic Outlook & Implications:

From an Indian perspective, the Thailand-Cambodia conflict is of special interest because it directly impacts India’s Act East Policy and becomes a hurdle in the larger Indo-Pacific engagement. The major concern areas are the Indian initiatives of connectivity projects in Southeast Asia, like the India-Myanmar-Thailand Trilateral Highway, whose viability depends on the stability in the relations of the two countries. Moreover, the Mekong-Ganga Cooperation framework, in which Thailand, Cambodia, and India are participants, also comes under threat as the major sectors of cooperation, like transport, tourism, culture, and communication getting hampered because of the conflict. It can potentially erode India's efforts at expanding its soft power influence in the region. The supply chains in the region are deeply integrated into the ASEAN networks of manufacturing and logistics. 

Thus, the rise in premiums as a result of the conflict directly impacts the Indian businesses' operations in Southeast Asia. Indian tourism too has been affected as official advisories have been issued by the Government of India. New Delhi continues to support ASEAN-led de-escalation efforts, prioritizing the functionality of the trade and connectivity routes.

Conclusion:

The Thailand-Cambodia border issue is not a result of a disagreement over temple ownership, but it is about the claims over cultural origins, it is about reclaiming what was lost to the colonial dissections of Southeast Asia, and it is about the contemporary security concerns that have emerged. In the midst of this contestation, it is the material cultural heritage of the Temple of Preah Vihear that is being damaged. The conflict is not of contemporary origins but has always existed in some way or the other. Cambodia and Thailand, which were once considered to be the closest of allies in the region, suffer today from security dilemmas and ambiguities over territorial rights. 

The blame for the recent escalations can not be taken by one country either. Rather, what the issue should be understood as is a failure of regional multilateral bodies (like ASEAN) and international bodies (like the ICJ) to bring this issue to a rest. It goes on to show how legal settlements for issues are not enough unless there is an overarching imposing authority. In international relations, states exist horizontally and do not follow a vertical hierarchy of power. Thus, the only way of resolving such disputes is by dialogue and confidence-building measures while attempting to reach an agreement that is mutually beneficial rather than selectively exploitative. The conflict between the two countries becomes a hurdle in the greater efforts of regional integration, both economically and politically. 

The future of functional connectivity lies in ASEAN’s ability to pursue effective regional security management. The roadblocks to this regional integration become a point of concern for not just countries in the region but also for countries like India, which remain key stakeholders in Southeast Asia. Especially for India’s Act East policy and infrastructure, and cultural projects like IMT Trilateral Highway and the GMC, the conflict only causes delays and produces unpredictability about the future of investments in the region. Therefore, a timely and peaceful de-escalation and reduction of hostilities should remain the priority for all the actors involved, since the sooner there are normalisation of political ties, the faster the investments will flow back into the region to build deeper economic interdependence and ensure a prosperous future for Southeast Asia and the Global South.

BY TEAM GEOSTRATA