{"id":10663,"date":"2026-06-16T10:29:21","date_gmt":"2026-06-16T04:59:21","guid":{"rendered":"https:\/\/shailandpartners.com\/blogs\/?p=10663"},"modified":"2026-06-16T10:29:22","modified_gmt":"2026-06-16T04:59:22","slug":"revisiting-the-outcomes-of-maritime-boundary-delimitations-lessons-from-india-bangladesh-for-cambodia-thailand","status":"publish","type":"post","link":"https:\/\/shailandpartners.com\/blogs\/revisiting-the-outcomes-of-maritime-boundary-delimitations-lessons-from-india-bangladesh-for-cambodia-thailand\/","title":{"rendered":"REVISITING THE OUTCOMES OF MARITIME BOUNDARY DELIMITATIONS: LESSONS FROM INDIA-BANGLADESH FOR CAMBODIA-THAILAND"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\"><strong>IN BRIEF<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Cambodia and Thailand have commenced UNCLOS conciliation proceedings to address overlapping maritime claims in the Gulf of Thailand, an area believed to contain substantial hydrocarbon reserves.<\/li>\n\n\n\n<li>There are several relevant precedents that the conciliation may utilise from the 2014 India-Bangladesh maritime boundary arbitration, specifically relying on the legal principles that guided the delimitation exercise, including equity, relevant circumstances and the management of overlapping maritime entitlements.<\/li>\n\n\n\n<li>One of the greatest takeaways from the India-Bangladesh arbitration is particularly regarding the separation of delimitation from resource exploitation and the use of cooperative arrangements.<\/li>\n\n\n\n<li>Every delimitation exercise today is not just about boundaries and sovereignty. The impact of unresolved maritime claims on foreign investment, resource development and commercial certainty in contested maritime areas is of prime importance today.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>INTRODUCTION<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In June 2026, Cambodia and Thailand commenced UNCLOS conciliation proceedings to address overlapping maritime claims in the Gulf of Thailand, including a 27,000-square-kilometre area believed to contain oil and natural gas reserves worth approximately USD 300 billion. The process was triggered by Thailand&#8217;s revocation of a 2001 MoU on joint development and resource sharing and comes amid broader territorial tensions between the two States. While the conciliation is non-binding, it represents an important attempt to resolve the dispute through international law.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This article examines the ongoing Cambodia-Thailand conciliation through the lens of the 2014 India-Bangladesh maritime boundary arbitration under UNCLOS Annex VII. It explores the similarities and differences between the two processes, the lessons that may be drawn from the India-Bangladesh Award, and the implications of maritime delimitation disputes for private parties and investment in contested maritime areas.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>THE COMPLICATIONS OF DELIMITATION<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The UNCLOS grants each coastal State its own maritime zones: a 12 nautical mile territorial sea, a 24 nautical mile contiguous zone, a 200 nautical mile exclusive economic zone and a continental shelf. States enjoy certain preferential rights in these zones, most importantly, the right to utilise marine resources and the right to undertake scientific research. Geography does not allow most States to enjoy all of their zones to the full extent granted by UNCLOS. The proximity between two or more States\u2019 coasts creates issues regarding the proper sharing of these zones. Formally, delimitation is the process of dividing two or more States\u2019 overlapping maritime zones equitably, so that each State may have an equitable share of the maritime zones as its neighbours. Delimitation is, by itself, a complicated process. The presence of islands, rocks, and low-tide elevations, each with its own specialised rules under the UNCLOS, only adds to the complication.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For decades, maritime boundary delimitation in the Bay of Bengal remained a highly volatile geopolitical friction point among India, Bangladesh, and Myanmar for precisely this reason. The unique geography of the Bay, characterised by a severely concave coastline, massive sediment deposition from the Ganges-Brahmaputra-Meghna river system, and shifting low-tide elevations, negated simplistic bilateral drawing of lines. Bangladesh initiated compulsory arbitration proceedings against India under Annex VII of UNCLOS in 2009. In the culminating 2014 arbitral award, a Permanent Court of Arbitration (PCA) tribunal awarded Bangladesh approximately 19,467 square kilometres out of the 25,602 square kilometres of contested maritime territory (roughly 76% of the disputed area). The Award is binding, and both India and Bangladesh have drawn their boundaries in compliance with the Award.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Delimitation in the Gulf of Thailand is similarly complicated by the uneven coastlines of the two States and the presence of islands in the Gulf with contested sovereignties. This, in part, is the result of an ambiguous border agreement between colonial France and the Kingdom of Siam, called the Franco-Siamese Treaty of 1907. The 2001 MoU was implemented between both parties to override ambiguous claims in the 1907 treaty and allow for an equitable arrangement for resource sharing. &nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>HOW THE TRIBUNAL DECIDED IN INDIA-BANGLADESH?<\/strong><\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>The Methodological Clash: Equidistance vs. Angle-Bisector<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">The foundational legal conflict between India and Bangladesh consisted of several issues, including (i) the manner of drawing baselines along the two States\u2019 coasts, the extent of the EEZ and continental shelf under Articles 73 and 84 of the UNCLOS that both States are entitled to, and how the contested areas must be divided to ensure an equitable sharing of space and resources.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>India\u2019s Position: India advocated for the strict application of the equidistance\/relevant circumstances method. This standard three-stage process involves drawing a provisional equidistance line based on coastal base points, checking for special or relevant circumstances that might distort equity, and adjusting it accordingly. India argued that an equidistance line yielded a predictable, objective, and mathematically sound boundary.<\/li>\n\n\n\n<li>Bangladesh\u2019s Position: Bangladesh vehemently opposed a strict equidistance line. Due to the deep concavity of the Bay of Bengal, an unadjusted equidistance line drawn from the adjacent coasts of India and Myanmar would converge rapidly, cutting Bangladesh off from its maritime extensions and creating an inequitable &#8220;lock-in&#8221; effect. Dhaka instead petitioned for the angle-bisector method, which smooths out coastal irregularities to construct a more favourable line.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The Tribunal rejected Bangladesh&#8217;s plea to formally deploy the angle-bisector method, choosing instead to uphold the institutional sanctity of the equidistance\/relevant circumstances framework. However, the Tribunal acknowledged that the severe concavity of Bangladesh&#8217;s coast constituted a relevant circumstance that caused an impermissible cut-off effect. Consequently, it adjusted the provisional equidistance line westward, giving Bangladesh a widened path to the deep sea.<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>The technical conundrum of the \u2018Grey Area.\u2019<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">By adjusting the delimitation line to remedy Bangladesh\u2019s cut-off effect, the Tribunal extended the boundary line into a zone where the continental shelf boundary of Bangladesh overlaps with the 200-nautical-mile EEZ boundary generated by India&#8217;s mainland coast. This legal anomaly created a grey area spanning roughly 5,220 square kilometres. This area was meant to equitably split the waters and the continental shelf in a way that makes up for Bangladesh\u2019s disadvantaged position due to the concavity of its coast. Accordingly, the Seabed and Subsoil (Continental Shelf) in the grey area belong to Bangladesh, granting Dhaka sovereign rights over sedentary species and mineral resources, including oil and natural gas. The Water Column (EEZ), however, belongs to India, granting New Delhi exclusive rights over pelagic fisheries and navigation. The Tribunal left it open to both India and Bangladesh to implement co-operation agreements to determine resource sharing and jurisdiction over the grey area. While critics argue this split jurisdiction compromises state sovereignty and introduces enforcement challenges, it effectively prevented one State\u2019s unjustified disadvantage over a geographic peculiarity. preserving India&#8217;s access to the living resources of the water column.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>LESSONS FOR CAMBODIA-THAILAND<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Although critics viewed the India-Bangladesh Award as a loss for India because a larger portion of the disputed area was awarded to Bangladesh, maritime delimitation is not intended to produce winners and losers. Rather, it seeks an equitable outcome based on international law and geographic realities. A key lesson for Cambodia and Thailand is that delimitation need not be resolved simultaneously with resource exploitation. In India-Bangladesh, the Tribunal delimited maritime entitlements while leaving practical arrangements for overlapping rights to future cooperation, even creating a &#8220;grey area&#8221; where rights over the seabed and water column were divided between the two States.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">While the India-Bangladesh dispute was resolved through binding arbitration and the Cambodia-Thailand process is a non-binding conciliation, the latter should not be underestimated. UNCLOS conciliation has previously proven successful, most notably in the Australia-Timor-Leste dispute, which culminated in the 2018 Maritime Boundaries Treaty and a framework for the joint development of the Greater Sunrise gas fields. These precedents demonstrate that rules-based dispute resolution can provide practical and durable solutions to even the most complex maritime disputes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>HOW OVERLAPPING MARITIME DELIMITATION CLAIMS AFFECT INVESTMENTS<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Contested maritime delimitation claims frequently deter foreign investment, particularly in capital-intensive sectors such as offshore oil and gas exploration, seabed mining and commercial fisheries, because investors face uncertainty as to which State possesses jurisdiction to grant licences, regulate operations and protect investments. For existing investments, contesting sovereignty claims may result in legal difficulties, such as, for example, what State to bring a claim against for breach of investment protection promises. This legal uncertainty has repeatedly affected resource development projects. In the Timor Sea dispute between Australia and Timor-Leste, the development of the Greater Sunrise gas field was delayed for years pending resolution of maritime boundary and revenue-sharing issues, with the eventual UNCLOS conciliation placing significant emphasis on the economic consequences of the dispute. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Similarly, in the East China Sea, competing maritime claims between China and Japan have complicated hydrocarbon exploration and discouraged unilateral development due to the risk of diplomatic protests and competing assertions of jurisdiction. Fisheries are equally affected, as overlapping claims often result in conflicting licensing regimes, enforcement actions and arrests of fishing vessels, thereby increasing operational and political risk for fishing operators. UNCLOS jurisprudence and commentary generally recognise that unilateral exploitation of natural resources in disputed maritime areas may violate the obligation not to prejudice a final boundary settlement, further discouraging investors who require long-term legal certainty before committing substantial capital.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>CONCLUSION<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The India-Bangladesh Award demonstrates that maritime delimitation is aimed at achieving equitable outcomes rather than producing winners and losers. Its innovative approach, including the creation of the &#8220;grey area,&#8221; highlights the flexibility of the UNCLOS framework and the importance of cooperation between States. Although the Cambodia-Thailand dispute arises in a different context, the principles of equity, practical resource-sharing and rules-based dispute resolution remain equally relevant. Whether through arbitration or conciliation, legal certainty in maritime boundaries is critical to promoting investment, resource development and regional stability.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>IN BRIEF INTRODUCTION In June 2026, Cambodia and Thailand commenced UNCLOS conciliation proceedings to address overlapping maritime claims in the<\/p>\n","protected":false},"author":2,"featured_media":10664,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-10663","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/posts\/10663","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/comments?post=10663"}],"version-history":[{"count":1,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/posts\/10663\/revisions"}],"predecessor-version":[{"id":10665,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/posts\/10663\/revisions\/10665"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/media\/10664"}],"wp:attachment":[{"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/media?parent=10663"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/categories?post=10663"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/shailandpartners.com\/blogs\/wp-json\/wp\/v2\/tags?post=10663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}