A conciliation meeting between Thailand and Cambodia over long-standing overlapping maritime claims began in Singapore on September 15, marked by sharply contrasting opening statements from both sides. The meeting, held at the Permanent Court of Arbitration’s (PCA) Singapore office, is part of a compulsory conciliation process initiated under the United Nations Convention on the Law of the Sea (UNCLOS) to resolve the dispute peacefully and in accordance with international law.

Cambodian Foreign Minister Prak Sokhonn, who also serves as Deputy Prime Minister, opened the session by framing the conciliation as a constructive step taken by Phnom Penh after Thailand unilaterally canceled a 2001 memorandum of understanding (MOU) on maritime cooperation. The MOU governed a disputed maritime zone of approximately 26,000 square kilometers, believed to hold substantial natural gas and oil reserves valued at around US$300 billion. Prak described the process as a means to rebuild trust and expressed hope that it would lead to an agreed maritime boundary delimitation treaty or a joint development arrangement for resource sharing. Should negotiations fail, Cambodia intends to seek recommendations from the commission.

In contrast, Thai Foreign Minister Sihasak Phuangketkeow, who also holds the post of Deputy Prime Minister, delivered a critical response, accusing Cambodia of making “self-serving” claims and engaging in false narratives against Thailand. He rejected Cambodia’s characterization of events, asserting that Thailand had proposed direct talks and a mutual move to conciliation before the dispute escalated. Sihasak cited historical incidents, including Cambodian rocket attacks and landmine injuries affecting Thai civilians and soldiers, to challenge Cambodia’s adherence to international law. He emphasized that the conciliation should not address sovereignty over land, specifically reaffirming Thailand’s claim to Koh Kood island, and dismissed Cambodia’s 1972 continental shelf claim line as lacking legal basis.

The conciliation, expected to last up to a year, does not produce legally binding decisions but aims to facilitate dialogue and potentially a negotiated resolution. Observers note that compulsory conciliation—a rarely invoked mechanism previously employed in a 2016 dispute between Timor-Leste and Australia—offers a structured forum for dialogue that might ease tensions and bridge differences.

Analysts highlight the disparity in power between the two countries, with international law mechanisms providing smaller states like Cambodia a platform to assert their claims more effectively. Hunter Marston, director of the Southeast Asia program at the Lowy Institute, pointed out that Thailand’s reluctance to engage in arbitration may be constrained by the compulsory nature of the conciliation process. Meanwhile, Cambodian experts see the proceedings as a pragmatic way to manage an intractable dispute and open channels for potential cooperation.

Bilateral relations between Cambodia and Thailand remain fraught following border clashes in July 2025, which temporarily subsided but left tensions high. The public’s reaction in both countries has been polarized, with social media users vigorously defending their respective governments’ positions.

Despite the initial confrontational tone, officials from both sides expressed openness to the conciliation process. Prak expressed optimism that the commission could help turn a new page in bilateral relations, while Sihasak affirmed Thailand’s readiness to work constructively within the framework to seek an equitable resolution.

Singapore’s role as the meeting venue underscores its neutral position, and with the city-state scheduled to chair the Association of Southeast Asian Nations (ASEAN) in 2027, the dispute between Thailand and Cambodia is expected to remain a regional focus. Future conciliation sessions may rotate among PCA offices worldwide depending on logistical convenience. Observers remain cautiously hopeful that the legal framework can help both nations advance toward a peaceful settlement amid ongoing political sensitivities.