Cambodia, Thailand: Sea Dispute Conciliation Panel Meets

• Cambodia and Thailand are engaged in UNCLOS-backed conciliation in Singapore over competing claims to seabed in the Gulf of Thailand, rich in untapped energy resources.
• The five-member panel, supported by the Permanent Court of Arbitration, will propose terms for a deal, but cannot impose a settlement.
• The dispute dates back to the early 1970s, with a negotiating framework adopted in 2001 failing to yield a resolution before Thailand withdrew from it recently.
• Both nations' foreign ministers presented conflicting narratives regarding the breakdown of previous talks and the motivations behind the conciliation.
• Thailand's historical aversion to third-party arbitration, stemming partly from the 1962 International Court of Justice Preah Vihear ruling, adds complexity to the current proceedings.

Although states can be compelled to participate in such a process, the panel's recommendations are non-binding.

Cambodia and Thailand recently engaged international conciliators in Singapore to address their long-standing maritime boundary dispute in the Gulf of Thailand. Both Southeast Asian nations assert claims over the same seabed, an area known to hold significant untapped offshore energy resources, including natural gas and other hydrocarbons. While Cambodia seeks either a defined maritime boundary or an agreement to share these valuable resources, Thailand also desires a negotiated boundary but contends that Cambodia's claims lack legal foundation.

This conciliation process involves a five-member panel, administratively supported by the Permanent Court of Arbitration, which convened over two days. The panel's role is to hear the arguments and objections from both countries and subsequently propose terms for a potential resolution. However, the conciliators do not possess the authority to impose a settlement, meaning any final agreement would require the voluntary consent of both Cambodia and Thailand.

The current proceedings operate under the framework of the United Nations Convention on the Law of the Sea (UNCLOS), which provides mechanisms for resolving certain maritime boundary disputes through compulsory conciliation when direct negotiations have failed. Although states can be compelled to participate in such a process, the panel's recommendations are non-binding. This particular Cambodia Thailand sea dispute conciliation follows decades of unresolved issues, with Cambodia first outlining its seabed claim in 1972 and Thailand issuing a royal proclamation in 1973.

Despite maritime discussions commencing in April 1995 and a negotiating framework being adopted in 2001, no agreement on a Cambodia Thailand maritime boundary or joint development ever materialized. The situation escalated recently when Thailand unilaterally withdrew from this framework on May 5, a move that Cambodian Foreign Minister Prak Sokhonn cited as the reason for his country's decision to pursue international conciliation the following month. This withdrawal occurred amidst a significant deterioration in bilateral relations, marked by armed conflict over land border territory in July and December 2025, which resulted in numerous casualties and displaced hundreds of thousands of people.

Both foreign ministers presented contrasting accounts of the dispute's progression and underlying issues. Cambodian Foreign Minister Prak Sokhonn emphasized that his nation views the conciliation as a path to rebuild trust, not an escalation, highlighting the potential for offshore resources to fuel industrial growth in a country still recovering from past devastation. He also called for adherence to existing bilateral agreements to aid displaced villagers and protect cultural sites damaged during recent conflicts.

Conversely, Thai Foreign Minister Sihasak Phuangketkeow argued that 25 years of talks had yielded only two official rounds, and Thailand's decision to scrap the framework was intended to invigorate negotiations. He stated that Thailand had previously offered six months of direct talks, to be followed by conciliation if necessary, an offer he claimed Cambodia ignored. Phuangketkeow also stressed that the current proceedings pertain exclusively to rights at sea, not land ownership, including Ko Kut island, while simultaneously accusing Cambodia of undermining trust through public claims, a leaked call between leaders, rocket attacks, and landmines. Thailand has historically preferred bilateral resolution for territorial matters, viewing a 1962 International Court of Justice ruling that awarded Cambodia the Preah Vihear temple as unfair, which has contributed to ongoing tensions.

Despite the non-binding nature of the panel's recommendations, this compulsory conciliation for maritime disputes holds significant weight for both nations. Cambodian Foreign Minister Prak Sokhonn underscored the potential for offshore resources to drive economic development, while Thai Foreign Minister Sihasak Phuangketkeow acknowledged that the process would influence bilateral relations long after its conclusion, asserting that it is not an exercise in zero-sum diplomacy. Thailand, despite its historical aversion to third-party arbitration, pledged constructive participation.

This process, supported by the Permanent Court of Arbitration, represents a crucial attempt to navigate a complex and long-standing Cambodia Thailand sea dispute, offering a structured platform for dialogue that could pave the way for a resolution regarding the Cambodia Thailand maritime boundary and the lucrative Gulf of Thailand offshore resources.

This case demonstrates the application and limitations of UNCLOS compulsory conciliation for resolving complex, long-standing maritime boundary and resource disputes. Lawyers advising states or energy sector clients should observe this process for insights into international dispute resolution strategies and potential impacts on offshore resource development in contested zones.

Source: Original reporting via Courthouse News