Thailand’s new government, led by Prime Minister Paetongtarn Shinawatra, has reignited hopes for resolving a decades-long territorial dispute with Cambodia over a lucrative offshore oil and gas field. This area, believed to contain resources worth over $300 billion, has been a source of tension between the neighboring nations since the 1970s. The exploration of this disputed region is now one of the top priorities of Shinawatra’s administration, which seeks to address Thailand’s energy crisis and growing reliance on expensive fuel imports.
The 26,000-square-kilometer zone, known as the Overlapping Claims Area (OCA), is believed to house vast quantities of natural gas—estimated at 10 trillion cubic feet—along with 300 million barrels of crude oil. For both countries, these resources could prove transformative, providing energy security and substantial revenue. However, the path to joint exploration is fraught with challenges due to the countries’ complex history of diplomatic spats, the delicate issue of sovereignty, and stalled negotiations that have lingered unresolved for over two decades.
Thailand, facing dwindling domestic gas supplies, is grappling with an energy crisis. Natural gas powers roughly 60% of the country’s electricity grid, with domestic production accounting for the majority of that supply. However, at the current rate of consumption, Thailand’s gas reserves could be depleted within five to 10 years, according to energy experts.
As a major hub for industries such as automotive manufacturing and tourism, Thailand’s rising energy needs are urgent, and without new supplies, the country risks having to rely on expensive liquefied natural gas (LNG) imports. This would drive up utility costs, burden businesses, and strain household budgets at a time when Thailand is trying to recover from the economic shock of the COVID-19 pandemic.
Prime Minister Shinawatra’s administration, which took office in September 2024, has emphasized that securing affordable and reliable energy is a critical priority. Restarting negotiations with Cambodia to jointly develop the OCA is a key element of the government’s broader strategy to contain soaring fuel prices and reduce the nation’s ballooning energy import bill.
The financial stakes are high, with former Thai energy minister Pichai Naripthaphan estimating that the natural gas and oil reserves in the disputed area are worth at least 10 trillion baht ($300 billion). Successful joint exploration could extend Thailand’s offshore gas production by at least two decades, according to Kurujit Nakornthap, executive director of the Petroleum and Energy Institute of Thailand.
The joint development of the OCA has long been seen as an attractive solution to the energy dilemma, but progress has been hampered by the issue of territorial sovereignty. The dispute between Thailand and Cambodia over this area stems from overlapping claims in the Gulf of Thailand, with neither side willing to fully cede control or compromise on sovereignty.
Efforts to resolve the dispute date back to the 1970s, but negotiations have stalled repeatedly, most recently in 2001 when both nations agreed that territorial claims and resource development should be addressed simultaneously. While there have been occasional moments of diplomatic thaw, mistrust and national sensitivities over sovereignty have consistently derailed discussions.
Now, however, the pressing need for energy on both sides of the border may provide the necessary momentum to break the stalemate. Finance Minister Pichai Chunhavajira, speaking in parliament last month, expressed optimism that the urgency of Thailand’s energy crisis could lead to a pragmatic solution. “We don’t need to resolve the different opinions on boundaries; we just need to have neighborly chats and try to make use of the resources,” he said, noting that such a move would improve energy security and reduce electricity costs for Thai consumers.
Cambodia, for its part, has shown willingness to reengage in talks. Cambodian government spokesperson Pen Bona affirmed the country’s readiness to continue negotiations with Thailand, stating, “If the new government of Thailand is ready, we are happy to continue the negotiations.”
The OCA, located in the Gulf of Thailand, holds significant untapped potential. The area is thought to contain around 10 trillion cubic feet of natural gas—enough to power Thailand for years to come—and about 300 million barrels of oil.
Several international oil and gas companies, including industry giants Chevron Corp., Shell Plc, and Thailand’s PTT Exploration & Production Pcl, won exploration concessions in the 1970s but have been unable to begin operations due to the ongoing territorial dispute. More recently, local media reports suggest that ConocoPhillips and TotalEnergies SE were awarded concession rights in Cambodia.
The potential for significant revenue from these reserves has only increased over time, but so have the risks. Cambodia, which lacks a robust domestic oil and gas industry, remains highly dependent on energy imports and could stand to benefit greatly from any deal. However, analysts note that Thai producers and contractors would likely undertake the bulk of the work in the disputed area, and Thai companies would emerge as the primary beneficiaries.
A report from Bangkok-based consultancy CLC Asia noted last year that “regardless of the revenue sharing model, Thai companies would walk away the biggest winners” from any joint development project in the OCA.
While Thailand has had some success in resolving similar disputes—such as its 1979 agreement with Malaysia to jointly explore a smaller area in the lower Gulf of Thailand—the situation with Cambodia presents more complex political challenges. The countries’ overlapping claims, dating back more than four decades, have been difficult to untangle due to concerns over ceding territory and compromising national sovereignty.
Critics of the current push for joint exploration warn that failing to resolve the issue of sovereignty before proceeding with resource development could spark domestic backlash. Former Thai senator Somchai Swangkarn has voiced concern that any perceived compromise on Thai sovereignty could lead to political instability. “If it proceeds, the negotiation won’t be finished, but the government will,” he said, warning that the public may not tolerate any agreement that appears to weaken Thailand’s territorial claims.
Somchai’s argument reflects the broader political landscape in Thailand, where national pride and sensitivity to territorial issues often run high. Some lawmakers believe that Thailand should first seek to establish clear boundary delimitations with Cambodia before moving forward with exploration. However, this approach could delay resource development for years, if not decades, given the complexity of the territorial dispute.
Despite the challenges, there are reasons for optimism. Both Thailand and Cambodia have publicly expressed their willingness to engage in renewed negotiations, and the current energy crisis may provide the external pressure needed to drive both sides toward a compromise. Cambodia, while less eager than Thailand to rush the negotiations, stands to gain from any agreement that allows it to tap into the region’s vast resources.
Moreover, there is precedent for a successful agreement between the two countries. The 1979 joint development agreement between Thailand and Malaysia, though covering a smaller area, demonstrates that mutually beneficial solutions are possible even in disputed territories.
Much will depend on the willingness of both governments to prioritize economic and energy security over political concerns. With Thailand’s new government showing a strong commitment to resolving the issue and Cambodia signaling its openness to talks, the possibility of a breakthrough appears more likely than at any time in the past two decades.
The next few months will be crucial as both nations attempt to navigate the complex intersection of diplomacy, economics, and national pride. If successful, the joint exploration of the OCA could not only secure much-needed energy for both countries but also mark a new era of cooperation between Thailand and Cambodia, setting a precedent for resolving other regional disputes in Southeast Asia.
