Thailand, Cambodia seek to calm escalating dispute over US$300 billion seabed

Thailand and Cambodia agreed on confidence-building measures to lower tensions over their disputed Gulf of Thailand waters. The measures matter because hostile statements, misinformation, or a naval incident could damage the fragile mediation process and inflame public opinion in both countries.

Both sides promised restraint in public communications about the maritime boundary and their bilateral relationship. They also agreed that navy commanders will use a hotline for prompt notification and management of maritime incidents. This should help prevent misunderstandings and reduce pressure during negotiations.

The agreement does not settle ownership of the 27,000 sq km sea wedge. It creates a calmer setting for the UN-backed conciliation process at The Hague. The process is not legally binding, so its success depends on both governments implementing the measures in earnest and continuing peaceful discussions.

The contested seabed is the underwater ground beneath a disputed wedge of the Gulf of Thailand. Thailand and Cambodia both claim rights over the maritime area, which covers about 27,000 sq km. The dispute concerns control of the waters and the resources beneath them.

The seabed matters because it contains oil and gas reserves estimated at US$300 billion. Control could affect which country explores for, develops, and benefits from those resources. The competing claims have therefore become a major source of tension alongside the countries’ unresolved land-border dispute.

Thailand ended a bilateral channel governing the claims in May. Cambodia then asked a United Nations maritime-law conciliation commission to begin mediation. The Permanent Court of Arbitration is hosting further discussions, but the process is not legally binding and has not yet determined ownership or exploitation rights.

The disputed maritime area is enormous by the standards of a bilateral boundary disagreement. It covers a 27,000 sq km wedge of the Gulf of Thailand, equal to about 10,400 square miles. The area is contested by Thailand and Cambodia.

Its economic importance is even more striking. The seabed is believed to hold oil and gas reserves worth an estimated US$300 billion. That potential wealth explains why the maritime claims have become more intense, especially after the countries’ bilateral negotiating channel was scrapped.

The figures describe potential value, not money already earned. No final agreement on control or development has been reached. Cambodia requested UN-backed conciliation, and talks continued at the Permanent Court of Arbitration in The Hague, where both sides agreed to reduce tensions while the process proceeds.

Thailand and Cambodia have disputed their boundaries for decades on both land and sea. Their land border stretches about 800km, and the article describes repeated disagreements over its demarcation. The maritime dispute adds competing claims over a resource-rich area in the Gulf of Thailand.

The conflict has had serious consequences. Clashes along the land frontier last year killed scores on both sides and froze billions of dollars in cross-border trade. The countries also accuse each other of targeting civilians, while nationalist arguments have spread across social media.

Relations remain damaged despite a December ceasefire along the frontier. Thailand scrapped its bilateral maritime channel in May, and Cambodia sought international conciliation. The disputes now combine unresolved boundaries, valuable resources, public mistrust, and political pressure, making compromise difficult even as both sides publicly support peaceful resolution.

A renewed rise in tensions could damage more than naval relations. The article warns that incidents, hostile communications, misinformation, and disinformation could undermine the conciliation process and worsen public sentiment in both countries. That would shrink the political space for compromise.

For example, an incident at sea could be misunderstood without prompt communication between commanders. Nationalist social-media disputes could then amplify competing accusations, as happened over alleged land encroachment and traditional clothing. The agreed hotline is intended to notify and manage maritime incidents before they create broader tensions.

The risks are serious because the countries already have a history of clashes and an uneasy ceasefire. Previous fighting killed scores and froze billions of dollars in trade. The latest measures may help, but the process is non-binding. Both governments must exercise restraint and advance the safeguards in earnest.

The United Nations Convention on the Law of the Sea, or UNCLOS, supplies the international legal framework behind Cambodia’s request for conciliation. Its process gives states a structured way to address maritime disputes when competing claims cannot be resolved bilaterally.

Cambodia asked a UNCLOS conciliation commission to begin mediation after Thailand scrapped their bilateral channel. The five-member commission is chaired by Australian lawyer and diplomat Katrina Cooper. The Permanent Court of Arbitration hosts the discussions at the Peace Palace in The Hague and reports on agreed confidence-building measures.

Neither institution has yet awarded the disputed waters to either country. The conciliation process is not legally binding. It is only the second use of UNCLOS conciliation, and the parties must continue negotiating. The process aims to support peaceful resolution while reducing rhetoric and preventing maritime incidents.

International maritime law generally determines seabed rights by identifying each coastal state’s maritime entitlements and then addressing where those entitlements overlap. States normally seek an agreed boundary through negotiation, guided by the law of the sea and the need for an equitable result. The article does not give the detailed legal formula used here.

In this dispute, Thailand and Cambodia claim a 27,000 sq km Gulf of Thailand wedge containing oil and gas. Their bilateral channel broke down in May, so Cambodia requested UNCLOS conciliation. The commission is helping the countries discuss the competing claims rather than granting immediate permission to exploit the seabed.

Until a boundary or cooperative arrangement is reached, the countries’ rights remain contested. The article does not state whether either side is currently extracting resources. The conciliation process is non-binding, so any final exploration or exploitation plan would require agreement or another applicable legal decision.