The fractured frontier: Why the Thailand–Cambodia crisis is the ultimate test for ASEAN centrality

This is no longer a routine border dispute. It is a systemic failure. The recent collapse of the Trump-brokered ceasefire in early December and the subsequent artillery exchanges in Pursat and Banteay Meanchey have proven that when nationalism meets energy desperation, ASEAN’s foundational promise that no two members would go to war is effectively dead.

Underpinning this land dispute is a much greedier reality, the Overlapping Claims Area (OCA) in the Gulf of Thailand. Both nations are locked in a zero-sum game over an estimated US$300 billion in oil and gas. Critics of the current Thai and Cambodian administrations argue that the MOU-44 framework, once hailed as a path to joint development, is being used as a political football. Hard line nationalists in Bangkok view any compromise as a surrender of sovereignty, while Phnom Penh sees the maritime wealth as a singular ticket to energy independence. This is the tragedy of the OCA, while both nations face an energy crunch, the resources remain trapped under the seabed by the weight of domestic political posturing. The conflict isn't about the 4.6 square kilometres of land around a temple, it is about the billions of dollars in fossil fuels that neither side can afford to leave behind, but both are too proud to share.

The most damning indictment of this conflict is the sheer scale of civilian suffering, which is often treated as a secondary statistic by regional leaders. As of late December 2025, official reports confirm that 700,000 people have been displaced across the frontier.

The data paints a grim picture of a region in retreat. According to the National Committee for Disaster Management (Cambodia), over 331,000 Cambodians have fled their homes, with 246,000 now living in makeshift government shelters. On the Thai side, the Defense Ministry confirms that 400,000 civilians have been evacuated across seven border provinces. These are not just displaced persons; they are families whose lives have been paused by the stroke of a military map. In Cambodia alone, 883 schools have been closed, stripping hundreds of thousand students of their education in a single stroke.

History is repeating itself with brutal efficiency. We saw this in 2011, and we are seeing it now on a much larger scale. For Cambodia, the flight of these civilians is a decapitation of local productivity. For Thailand, the humanitarian logistics are a massive drain on a state already struggling with its own internal divisions.

The economic data for the latter half of 2025 is nothing short of catastrophic. Before the July escalation, bilateral trade was on track to hit US$15 billion. Since the military took over border management and the primary checkpoints were shuttered, cross-border trade has plummeted by a staggering 99.9%.

In October 2025, Thai cross-border trade with Cambodia fell to a pathetic 9 million baht, down from an average of 27 billion baht per month in the previous year. This isn't just a temporary dip; it is a permanent reconfiguration of the regional economy. As Thai products vanish from Cambodian shelves, they are being replaced by Vietnamese and Chinese alternatives. Thailand is effectively legislating itself out of its own backyard, losing an estimated 120 billion baht in exports in just six months.

Thailand’s Strategic Blind Spot

Thailand’s military-centric approach to the border ignores a glaring internal reality, the Deep South. For twenty years, Thailand has poured over 500 billion baht into containing the Malay-Muslim insurgency in its southern provinces. By pivoting its primary combat units and F-16 air assets to the Cambodian border, Bangkok is creating a security vacuum in the South.

This distraction is a gift to insurgents. When state resources are spread thin across two active fronts, intelligence gaps widen and response times slow. For Malaysia, this is a nightmare scenario. A destabilized Southern Thailand inevitably bleeds across the border into Kelantan and Kedah, bringing with it weapons, radicalization, and more displacement.

As Malaysia leads ASEAN in 2025, Prime Minister Datuk Seri Anwar Ibrahim faces a grim inheritance. The ASEAN Way has been exposed as a tool for procrastination, not peace. The December 22 Special Foreign Ministers' meeting must be more than a photo opportunity.

For the ASEAN Secretariat, the time for non-interference as a shield for inaction is over. The Secretariat must be empowered to deploy independent monitors and facilitate binding dispute resolution. If the bloc cannot manage a conflict between its own members, it has no business claiming a central role in the wider Indo-Pacific.

For Malaysia, its role cannot be limited to hosting dinners and meetings. Under the theme of Inclusivity and Sustainability, Malaysia must champion an ASEAN Humanitarian Corridor and demand a transparent roadmap for the OCA and peace building in the region. We cannot afford to be neutrally silent while our neighbours burn. Silence today is a down payment on regional instability tomorrow.

The ongoing brinkmanship between Bangkok and Phnom Penh is no longer a private affair, it is an act of profound regional selfishness. By prioritizing myopic nationalist grandstanding over collective security, both nations are effectively holding the rest of Southeast Asia hostage. In an era of total economic and social integration, Thailand and Cambodia do not have the moral or political right to treat their border as a private sandbox for conflict. Regional stability is the collective crown jewel of ASEAN, and it is currently being gambled away for the sake of domestic political vanity.

A war between these two states would be a parasitic conflict, one that survives by draining the resources, security, and patience of its neighbours. Malaysia, Vietnam, and Laos cannot be expected to indefinitely absorb the externalities of this manufactured crisis, whether in the form of disrupted supply chains, broken energy markets, or the inevitable human tide of the displaced. Peace in Southeast Asia is not a luxury, it is a prerequisite for survival. The window for a diplomatic solution is closing, and for the 700,000 people sitting in bunkers today, the ASEAN Way feels less like a philosophy and more like an excuse. It is time for Malaysia and the ASEAN leadership to choose between the comfort of old protocols and the courage of active mediation.

Furthermore, this crisis must serve as the final eulogy for the ASEAN Way. The sacrosanct policy of non-interference has morphed from a diplomatic virtue into a doctrine of institutional paralysis. When non-interference becomes a shield that allows member states to sleepwalk into a regional catastrophe, it is no longer a policy, it is a suicide pact. ASEAN is already haemorrhaging credibility and resources over the protracted tragedy in Myanmar. The region is at a breaking point and quite simply has no more room for another humanitarian disaster.

The choice is now stark, ASEAN must either evolve beyond its outdated protocols to enforce active accountability, or it must accept its own irrelevance. Peace is not a bilateral gift that Thailand and Cambodia can choose to withhold. It is a regional obligation they must be forced to honour. The time for quiet concern has expired, the era of interventionist diplomacy must begin.

---

Tunku Nashril Abaidah is a Senior Lecturer at the Faculty of Administrative Science and Policy Studies, Universiti Teknologi MARA (UiTM) Kedah.