AKP Phnom Penh, June 15, 2026​ --

On June 2, Cambodia initiated compulsory conciliation proceedings with Thailand under the UN Convention on the Law of the Sea (UNCLOS). We did so to protect our national sovereignty and maritime rights after Thailand unilaterally walked away from a 25-year-old bilateral memorandum of understanding.

That MoU was intended to facilitate an agreement over where the maritime border should be drawn between our two countries, and how valuable undersea oil and gas deposits should be shared. Thailand has since agreed to join the UNCLOS conciliation process. This is a positive and welcome step.

The significance of this moment, however, is greater than a dispute between two countries. It offers us all a chance to collectively step up at the international, regional and local level.

First, it is a chance for the international community – great powers, middle powers and small states alike – to see effective international law in action. And, at a critical moment in history, to offer support to peaceful dispute resolution under the auspices of the UN when the multilateral rules-based order is under pressure.

Second, it is a chance for the ASEAN community to draw on the region’s rich history of mutual support and the organisation’s well-deserved reputation as a role model on the international stage. And third, it is a chance for Thailand and Cambodia – neighbours with a history together stretching back centuries – to step away from confrontation and choose peace.

There is reason for confidence. Ten years ago, compulsory conciliation under UNCLOS resolved a maritime dispute between Timor-Leste and Australia that had seemed intractable.

The asymmetry between those two states was stark: Australia’s population was 20 times bigger, its nominal GDP nearly 500 times larger and its military expenditure roughly 1,000 times higher.

Faced with that imbalance, Timor-Leste enlisted the assistance of international experts to break the deadlock through UN-led conciliation and agree on a permanent maritime boundary. At first, Australia opposed the process. Yet just two years later, an historic treaty was signed.

For Timor-Leste, the agreement was a nation-changing success. But Australia also praised the result. Why? Because both countries agreed to follow the rule of international law, not the rule of the strong over the weak.

Australia’s then-Foreign Minister Julie Bishop said the treaty “reflects the importance of UNCLOS” and “shows how international law can enable countries to resolve their disputes peacefully.”

That precedent speaks directly to Cambodia and Thailand today. The UNCLOS conciliation process will require good faith from both sides. It will also require consistency and pragmatism.

Consistency is essential. In the Timor-Leste case, Australia had every opportunity to suspend its engagement in bilateral cooperation and talks with Timor-Leste overseen by the conciliation commission. But it did not. It engaged consistently. Relations between the two neighbours improved as a result. And, in the end, a maritime boundary treaty was agreed.

Pragmatism is equally essential. The Cambodia-Thailand dispute is not merely an abstract legal problem. It concerns a real maritime area and real energy resources – resources that could contribute to economic security and development for both countries and the wider region.

A process that discusses only the lines on a map while refusing to address what lies within those lines would leave critical issues unresolved.

Cambodia is not asking the UNCLOS Conciliation Commission to impose a one-sided answer. We are asking for the process to address the issue as it is: a maritime-boundary dispute that has always been connected to the question of the peaceful development of energy resources.

We recognise that Thailand has national interests. Cambodia has national interests, too. International law does not require either side to abandon those interests. It requires both sides to pursue them peacefully, respectfully and within a rules-based framework.

The same commitment to peaceful resolution must extend to our shared land border. The current ceasefire between Cambodia and Thailand continues to hold, but it is fragile. Cambodia remains concerned by the situation on the ground in the occupied areas well inside Cambodian territory.

Borders and sovereignty must never be altered by force or fait accompli. On land just as at sea, steadfast adherence to international law and existing treaties and agreements, as well as dialogue, good faith and mutual respect, are key to ensuring that sovereignty, territorial integrity and international boundaries are respected.

Cambodia remains ready to engage peacefully and consistently with Thailand on all the issues we face, both on land and at sea. There are effective mechanisms to do so, as the UNCLOS process for the sea has shown.

Cambodia attaches great importance to its relationship with Thailand, a close neighbour with a common commitment to peace and prosperity in our region. We must, at all costs, continue to talk when the stakes are so high.

The maritime area must not become another theater of mistrust. And the land border must not see a further escalation of tension. Instead, Cambodia and Thailand should follow the tradition of how Southeast Asian states resolve difficult disputes.

The Timor-Leste case began with acrimony and ended with agreement. It began with uncertainty and ended with proof that compulsory conciliation under international law can break a deadlock and resolve disputes when bilateralism has run its course.

Cambodia welcomes Thailand’s engagement in the UNCLOS conciliation process. We ask that all sides engage in good faith. Our peoples, our region and the world will bear witness.

By Prak Sokhonn

Deputy Prime Minister and Minister of Foreign Affairs and International Cooperation of the Kingdom of Cambodia

For Asia Times

June 13, 2026