Thailand and Cambodia's 25-Year Dispute Over Gulf Gas Reserves Remains Unresolved

Thailand and Cambodia are entangled in a 25-year dispute over vast offshore oil and natural gas reserves in the Gulf of Thailand, estimated to be worth $300 billion. The core of the conflict lies in the Overlapping Claims Area (OCA), a 26,000-square-kilometer zone where both nations assert maritime rights. This unresolved boundary issue has effectively halted exploration and development, casting a shadow over both countries' energy security, government revenues, and regional stability. Estimates suggest potential reserves of 11 to 12 trillion cubic feet of natural gas and 300 million to 700 million barrels of oil. However, these figures represent potential resources, not proven reserves ready for production. Accurate assessment requires detailed geological studies and a resolution to the overlapping claims. For companies to proceed with development, clarity is needed on who can authorize exploration, how revenues would be divided, and which maritime boundary applies. Rising political friction has also impacted broader cooperation, as evidenced by past diplomatic breakdowns between the two nations. The 2001 Memorandum of Understanding (MoU 44) offered a framework for discussing joint development, but it became entangled with the sensitive issues of territorial sovereignty and resource exploration. Thailand formally terminated MoU 44 on May 5, 2026, though discussions under the United Nations Convention on the Law of the Sea (UNCLOS) remain a possibility. As long as the legal framework for the OCA remains unsettled, companies face uncertainty regarding permits, taxation, production rights, and revenue sharing. Even with a strong economic case for exploration, the resources will likely remain undeveloped. This dispute transcends mere resource development, representing a complex geopolitical challenge involving national sovereignty and interests, making a swift resolution unlikely.