Indian Council of World Affairs

Introduction

The Gulf of Thailand, a semi-enclosed sea bordered by Thailand, Cambodia, Vietnam, and Malaysia is a significant water body in the Indo-Pacific Region. The Gulf of Thailand is a crucial maritime corridor for the littorals, which is not seen as an area with maritime conflicts. However, this region has its set of challenges in the form of overlapping maritime boundaries and Exclusive Economic Zones (EEZs) claims which can have significant implications for the peace and stability in the larger Indochina, Southeast Asia, and the Indo-Pacific region. 

The Gulf spans approximately 320,000 square kilometres, with shallow depths with a maximum depth of 80 meters. The Gulf is narrow in size with a width varying between 480 to 560 kilometres and a length being around 720 kilometres (See Map 1).[i]The Gulf is a principal maritime outlet for Thailand and the only outlet for Cambodia. Most of the commercial hubs including port cities like Bangkok and Pattaya in Thailand, and Sihanoukville in Cambodia are along the coast of the Gulf, while Ho Chi Minh City of Vietnam is near the Gulf.

Map 1: Gulf of Thailand

Source: Gulf of Thailand, https://www.worldatlas.com/gulfs/gulf-of-thailand.html.

Regarding the overlapping claim areas, some progress has been made through bilateral agreements, but unresolved disputes continue to pose challenges to regional stability and cooperation (See Map 2). 

In the case of Malaysia and Thailand, they signed a Memorandum of Understanding (MoU) in 1979 to establish the Joint Development Area (7,250 square kilometres).[ii] Another such agreement (MoU) was signed in June 1992 between Malaysia and Vietnam enabling joint petroleum exploitation in the Defined Area and establishing an authority that oversees the matters within the area. 

Since the 1990s, Cambodia and Thailand have been attempting to amicably settle their long-standing territorial dispute, which dates to the 1970s.Since late 2023 they have taken the initiative to resolve the dispute, however, it is still in progress. Although most of the disputes have seen some progress, the dispute between Cambodia and Vietnam has failed to achieve a breakthrough. Both countries view control over maritime areas as a matter of national pride and sovereignty.[iii] It also stems from the history of turbulent ties between the two countries.

Map 2: Overlapping Claim Areas in The Gulf of Thailand

Source:https://www.clc-asia.com/thailand-cambodia-overlapping-claims-area/

Resources in The Gulf of Thailand

One of the reasons for the territorial disputes in the Gulf does not stem only from the issues of national sovereignty or its importance as a sea lane for the littorals but also from the presence of significant amount of hydrocarbons. The littoral states have significantly utilized the resources from the Gulf to develop their economies, especially through fisheries and hydrocarbons. 

Hydrocarbons were first discovered in the Gulf of Thailand in the early 70s. Thailand's section of the Gulf holds significant reserves of oil and natural gas (See Map 3). Its notable reserves are in the Erawan and the Bangkot fields. As of 2024, the Gulf of Thailand has 47 fields, out of which Thailand currently has 34 fields which together produce 75,000 barrels per day (bpd) and 2.4 billion cubic feet of gas per day. [iv]

Map 3: Oil and Gas Fields of Thailand

Source: https://www.og-advisors.com/countries/thailand

On the other hand, Cambodia's oil and gas industry is in its infancy and is still in the beginning stages of exploration compared to its neighbours. This can be attributed to the nation's turbulent political past, unstable economic foundation, and resultant social-political-economic structure.[v] Nevertheless, Cambodian Block A, located off the coast of Cambodia is the most promising area for hydrocarbon production (See Map 4). [vi] As of 2021, owing to technical challenges the Cambodian Block A’s output was below expectations producing 3,534 barrels per day while initially the production was expected to be producing 7,500 barrels per day. [vii] 

Map 4: Oil and Gas Fields of Cambodia

Source: https://opendevelopmentcambodia.net/oil-exploration-in-cambodia/

In terms of fisheries, as of 2020, Cambodia and Thailand have a cumulative catch of about 33,00,000 million tonnes of marine fisheries, inland fisheries, and aquaculture. Thailand has a significant share of around 24,00,000 million tonnes[viii] while Cambodia has a share of around 9,30,000 million tonnes[ix]. However, Cambodia is more dependent on inland fisheries and aquaculture compared to Thailand which has more produce from marine fisheries. The biggest challenge the region suffers from is not overfishing by these countries but Illegal, Unreported and Unregulated (IUU) fishing from other countries that are not littoral to the Gulf. 

In recent survey studies, there has been an indication of the presence of rare earth elements (REE) in the Gulf of Thailand's seabed and potential for wind energy. The Bay of Bangkok alone has a technical power potential of 7000 Megawatts.[x] The central and southern part of the Gulf has higher REEs like zircon, authigenic pyrite, and biogenetic limestone.[xi]

Geopolitics of The Gulf of Thailand

The foreign policy and external engagements of these four Gulf states are independent of each other. For instance, Thailand has been a close military partner of the United States since the post-Second World War era. This is evident from the regular military exercises conducted between both countries. Whereas Cambodia has been maintaining a close partnership with China. 

Thailand’s foreign policy is referred to as “bamboo bending with the wind” for its flexibility and its sense of independence that are maintained to preserve the state’s sovereignty and protect its national interests.[xii]However, it has had very close ties with the US post the Second World War especially on the political and military aspects. Thus, the US views Thailand as an important ally in the region. Thailand, however, strengthened its economic ties to Beijing for the past few decades at the same time and is also a part of several infrastructure projects under China's Belt and Road Initiative (BRI).[xiii]

In the case of Cambodia, China has been a significant economic partner and the largest investor in its infrastructure development sector.[xiv]Cambodia's rich hydropower, solar, and hydrocarbon resources provide opportunities for China to diversify its energy import sources beyond its traditional suppliers. Financing and constructing critical energy infrastructure in Cambodia aligns with China's goal of expanding its economic influence and having diplomatic leverage. 

Additionally, China and Cambodia inked a deal in 2019 that permits China to develop and utilize the Ream Naval Base located on Cambodia's coast. China has further given Cambodia military hardware and funding to modernize the base's facilities and build new facilities. However the US worries about the Ream Naval Base reached a critical level in 2019 after Cambodia abruptly refused US help for repairs there and demolished a facility that the US had funded in late 2020.[xv]Cambodia’s dependence on China has also raised the question of debt diplomacy. 

Vietnam on the other hand has a policy of not aligning with any country. This is seen in its Four No’s policy- no to an alliance, no to foreign military presence, no to taking sides in a dispute/ conflict between two other countries, and no using force or threatening to use force in international relations. [xvi] Malaysia has a similar position to Vietnam but one that has not been explicitly stated like Hanoi.

However, the South China Sea dispute, involving several Southeast Asian countries and China, can pose a significant problem to the regional security of the Gulf. Vietnam and Malaysia are part of both the South China Sea and the Gulf of Thailand. Therefore, their approach in the Gulf of Thailand would be seen in the context of their ongoing disputes with China and other claimants to the South China Sea. 

Apart from this, there is another development in this region which is of equal importance. One of the major points of contestation and why the Gulf of Thailand is significant for China is to solve its “Malacca Dilemma” where it fears the situations in which its trade in the Strait of Malacca faces blockades and becomes vulnerable in the event of hostilities from other countries. Thailand has recently come up with a US$ 27 billion project to create a Land Bridge across the Isthmus of Kra that would link the Andaman Sea and the Gulf of Thailand.[xvii] This project aims to serve as a strategic alternative to the Strait of Malacca, providing a faster, shorter, and cheaper route for international trade. This will make the Gulf of Thailand an important global Sea Lane of Communication (SLOC) and thus would result in the Gulf of Thailand becoming another focal point of international shipping and the global economy.

Conclusion

As the regional dynamics in the larger Indo-Pacific region continue to evolve which includes the contestation between the US and China, the Gulf of Thailand will play a role in shaping the growing geopolitical landscape of Indochina, Southeast Asia, as well as the Indo-Pacific region. This is so as the Gulf of Thailand is an integral part of the Indo-Pacific region and an important water body in this region. Thailand and Cambodia, the primary littorals of the Gulf, will play a greater role in shaping the dynamics of the region as this is their sole maritime gateway to the international SLOCs. Malaysia and Vietnam, the secondary players in the Gulf, are also parties to the South China Sea dispute which is significant for their security and foreign policy. However, they will pay close attention to any developments in the Gulf of Thailand, especially the role of the non-littorals as it will have implications on the South China Sea. In this regard, much will depend on how these four littorals balance their security, diplomatic, and economic interests, and their engagement with other littorals, non-littoral and extra-regional states beginning with fellow ASEAN Member States, the US and China. It is difficult for the geopolitical situation in the Gulf of Thailand to remain isolated from other tensions brewing and growing in the Indo-Pacific region.

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*D Manaswini Srivatsav, Research Intern, Indian Council of World Affairs, New Delhi
Disclaimer: Views expressed are personal.

Endnotes

[i]WattayakornGullaya, Review of Environmental Issues in the Gulf of Thailand. In The Environment in Asia Pacific Harbours, edited by Eric Wolanski, 249. https://link.springer.com/content/pdf/10.1007/1-4020-3655-8.pdf#page=256.

[ii]“Malaysia-Thailand Joint Authority.” Www.mtja.org. https://www.mtja.org/chronicle. Accessed July 16, 2024.

[iii] Amer, Ramses. 1997. Review of Border Conflicts between Cambodia and Vietnam . IBRU Boundary and Security Bulletin Summer 1997 , August. https://www.researchgate.net/publication/242202786_Border_Conflicts_between_Cambodia_and_Vietnam.

[iv] “Gulf of Thailand Oil and Gas Exploration Faces Stubborn Hurdles.” Gas Outlook. Accessed July 22, 2024. https://gasoutlook.com/analysis/gulf-of-thailand-oil-and-gas-exploration-faces-stubborn-hurdles/.

[v] Sripathi Narayanan. 2024. “Cambodia: China’s Gateway to the Gulf of Thailand?”. Indian Council of World Affairs (Government of India). 19 June 2024./show_content.php?lang=1&level=3&ls_id=10983&lid=6984&kval=sripathi%20narayanan.

[vi]Sothearak, Sok, and Khim Sotheara. “Cambodia’s Offshore Petroleum: Challenges and the Ways Forward.”https://rupp.edu.kh/iispp/cseas/cseas_insights/2024/documents/CSEAS%20Insight_Cambodia%27s%20Offshore%20Petroleum.pdf. Accessed July 11, 2024.

[vii] “Apsara Oilfield Project Offshore Cambodia May Not Be Viable.” 2021. Offshore. April 1, 2021. https://www.offshore-mag.com/production/article/14200539/apsara-oilfield-project-offshore-cambodia-may-not-be-viable.

[viii] “Fisheries Country Profile: Thailand.” SEAFDEC. 2017. http://www.seafdec.org/fisheries-country-profile-thailand/.

[ix] “Fisheries Country Profile: Cambodia.” SEAFDEC. http://www.seafdec.org/fisheries-country-profile-cambodia/.

[x]Vangtook, JarudateVorasee,PanuSuwicharcherdchoo,Prapapong. 2023. “Thailand Harnesses Wind Energy Potential.” T&D World. May 10, 2023. https://www.tdworld.com/renewables/article/21263029/thailand-harnesses-wind-energy-potential.

[xi] Liu, Shengfa, Xuefa Shi, Gang Yang, SomkiatKhokiattiwong, and NarumolKornkanitnan. 2016. “Distribution of Major and Trace Elements in Surface Sediments of the Western Gulf of Thailand: Implications to Modern Sedimentation.” Continental Shelf Research 117 (April): 81–91. https://doi.org/10.1016/j.csr.2016.02.002.

[xii]Tahir, R. S. A. R., & Huda, M. I. M. 2023. Thailand’s “Bamboo Bending with The Wind” Policy, Shifting Ground Between The U.S and A Rising China. International Journal of Academic Research in Business and Social Sciences, 13(2), 1611 – 1629.: http://dx.doi.org/10.6007/IJARBSS/v13-i2/16415

[xiii]Jack Sato, Rahman Yaacob. 2023. “Is China Replacing the US as Thailand’s Main Security Partner? | Lowy Institute.” Www.lowyinstitute.org. https://www.lowyinstitute.org/publications/china-replacing-us-thailand-s-main-security-partner.

[xiv] “China Plans to Invest in Cambodia’s Energy Sector.” Cambodianess. Accessed July 24, 2024. https://cambodianess.com/article/china-plans-to-invest-in-cambodias-energy-sector.

[xv] Woody, Christopher. 2024. “China’s Newest Military Base Abroad Is up and Running, and There Are More on the Horizon.” Breaking Defense. July 12, 2024. https://breakingdefense.com/2024/07/chinas-newest-military-base-is-up-and-running-and-us-officials-see-more-of-them-on-the-horizon/.

[xvi]Viet Tuan. 2023. “Vietnam Continues ‘Four Nos’Defense Policy - VnExpress International.” VnExpress International. August 2, 2023.https://e.vnexpress.net/news/news/vietnam-continues-four-nos-defense-policy-4637076.html.

[xvii]PichayadaPromchertchoo, Rhea Yasmine Alis Haizan. 2023.“Analysis: Thailand’s Proposed Land Bridge Project Easier than Kra Canal Idea, but Steep Challenges Await.” CNA. 20 October 2023. https://www.channelnewsasia.com/asia/thailand-srettha-thavisin-land-bridge-project-port-malacca-strait-canal-3860941.