Recent international jurisprudence reveals a tendency to constrain the continental shelf beyond 200 nautical miles (NM) in two principal respects. First, in relation to entitlement, courts have progressively limited the role of natural prolongation, treating it as subordinate to, or loosely applying it alongside, the distance criterion. This interpretation narrows the conditions under which a State may establish rights beyond 200 NM, thereby constraining the substantive scope of entitlement envisaged by Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS) and the practice of the Commission on the Limits of the Continental Shelf. Second, regarding delimitation, judicial bodies have relied on the notion of a single continental shelf to extend the same equitable boundary line used within 200 NM seaward, effectively subordinating the outer shelf to the inner shelf. These developments restrict both the legal and spatial reach of outer continental shelf claims, reshaping the interpretation of the continental shelf beyond 200 NM in ways that appear increasingly difficult to reconcile with the natural prolongation-based framework established under Article 76 UNCLOS.

International fisheries law has so far proven inadequate to prevent over-fishing on the high seas, a key cause of biodiversity loss in areas beyond national jurisdiction (ABNJ). The negotiation of the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement) provided an opportunity to respond decisively to the worsening problem. After some 20 years of preparation and negotiations, the BBNJ Agreement was concluded in 2023 and will enter into force in early 2026. From about mid-way through the process, the major distant-water fishing States advocated for a treaty text that minimised any significant impact upon their distant-water fishing operations. The terms of the BBNJ Agreement do not preclude its operationalisation contributing to a step change in protecting ABNJ from biodiversity loss by distant-water fishing operations but, at this point, such an outcome appears unlikely given the attitude of the distant-water fishing States during the negotiations, in combination with the institutional and decision-making provisions of the BBNJ Agreement.

Armed conflicts often spill over from the land to the sea, rendering the law of naval warfare key for governing such conflicts. Against this background, the United States Naval War College developed the Newport Manual on the Law of Naval Warfare (Newport Manual) in 2023, which attempted to codify the existing rules of customary international law. However, this manual differs from the San Remo Manual on International Law Applicable to Armed Conflicts (San Remo Manual), adopted in 1994, particularly regarding the rights of neutral coastal States over their exclusive economic zones (EEZs). While the San Remo Manual requires belligerents to have due regard for such rights, the Newport Manual assumes that such due regard is not required under customary international law. These divergences are derived from different understandings of the relationship between the United Nations Convention on the Law of the Sea (UNCLOS) and the law of naval warfare. This article analyses this by examining the two manuals as well as the domestic military manuals of maritime powers. It concludes that due regard should be paid to neutral States’ EEZ rights, but the standard of due regard during an armed conflict differs from that applicable during peacetime.

According to the Intergovernmental Panel on Climate Change’s Sixth Assessment Report, sea-level rise will continue for thousands of years. Many small island States and low-lying coastal States are already experiencing sea-level rise together with landward regression of coastal areas. This raises several legal questions, such as whether States are obligated to revise existing baselines, outer limits of maritime zones and charts. This article examines the legal lacunae in the United Nations Convention on the Law of the Sea (UNCLOS) concerning the legal consequences of sea-level rise on baselines and maritime boundaries, including islands and archipelagos. It provides an overview of the work of the International Law Commission on sea-level rise in relation to international law. It traces the evolution of States’ views within the Sixth Committee between 2018 and 2024 and the UN, as well as the recent Advisory Opinions on climate change of the International Tribunal for the Law of the Sea and the International Court of Justice. It concludes by noting how the legal lacunae in UNCLOS have been clarified, leaving to be determined the next steps in implementing the convergence of States’ interpretations of UNCLOS and customary international law in favour of preservation of baselines and maritime boundaries despite the physical effects of sea-level rise on coastlines.

Due regard obligations require both States and non-State actors to reasonably consider the rights or interests of other States or non-State actors when exercising their own rights and performing their duties. This article examines how due regard obligations should be interpreted in areas beyond national jurisdiction (ABNJ) in light of the adoption of the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement). As human activities in ABNJ increase, due regard obligations become crucial for balancing the competing rights and interests of States, non-State actors and relevant institutions, frameworks and bodies (IFBs). The literature and case law have mainly addressed conflicts between coastal and flag States concerning the application of due regard obligations within national jurisdictions. Different dynamics arise in ABNJ from potentially conflicting activities and disagreements between States with the same rights or interests, or those between States, non-State actors and IFBs. This article addresses this gap by analysing the new dynamics of due regard that are expected to arise concerning marine genetic resources and area-based management tools with the implementation of the BBNJ Agreement.

The article examines the widespread practice of using extended judicial formations to decide certain types of cases in higher courts, a practice present in many jurisdictions—whether appellate, apex or supranational. While the use of these formations, often considered the ‘most important’, is frequently debated within individual countries, a conceptual and comparative analysis providing a firmer theoretical foundation for these discussions is currently lacking. Departing from existing scholarship, which often assumes a universal purpose for these bodies, this article argues that jurisdictions tend to adopt one of two models of extended formations: the collective control model or the jurisprudential model. These models reflect divergent sources of legitimacy for the enlarged formations—either rooted in the broader participation of judges in the court’s decision-making process (input or procedural legitimacy), or in the doctrinal quality of the decisions that the grand chamber produces and their resulting consequences (output or performance-based legitimacy). These distinctions help to explain differences in how extended formations are composed, the types of cases they hear, the procedures they follow and how their decisions are drafted and subsequently used within the court. The article ultimately demonstrates that the choice between the two models reflects broader assumptions within different judicial systems about the nature of law and judging.

A significant impetus for the negotiation of the United Nations Convention on the Law of the Sea (UNCLOS) was the impact of new technological and scientific developments on the law of the sea. Such developments have continued apace, raising the question of how UNCLOS continues to respond to new uses of, and threats to, the oceans. This article focuses on marine geoengineering as an emerging technological response to the climate emergency and its regulation by the specialised global dumping regime of the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter and its Protocol within the general normative framework provided by UNCLOS. It demonstrates how responding to technological developments is hard-wired into the DNA of the law of the sea, and into UNCLOS in particular, which remains the foundation for the governance and management of new maritime technologies.

It is now generally accepted that human rights law applies at sea, yet uncertainty remains as to how it operates within the maritime domain. The United Nations Convention on the Law of the Sea contains few references to the treatment of individuals and many of the central concepts of the law of the sea that are reflected in it—such as functional zones of maritime jurisdiction, flag State jurisdiction and the freedoms of the seas—present challenges to the effective application of human rights law. Moreover, human rights law was developed with a terrestrial focus, making its application at sea equally problematic. This article argues that before practical solutions can be proposed to address this conflict of regimes, it needs to be recognised that human rights law does not apply at sea in the same way that it applies on land: the practical realities of the maritime environment shape the scope and content of rights. It argues that there is a need to clarify what constitutes a genuine human rights issue in the maritime domain, distinguishing these from other forms of poor treatment or regulatory non-compliance. It examines how the law of the sea and human rights law might interact more effectively, considering both conceptual and contextual adjustments necessary for realistic and enforceable protection of human rights in the maritime domain.

This foreword introduces the inaugural International and Comparative Law Quarterly (ICLQ) Forum, a new initiative designed to provide in-depth analysis of a particular field of law within the ICLQ’s sphere of interest. The first Forum focuses on the law of the sea, a subject with which the journal has been closely associated since its inception. The choice of theme reflects both the ICLQ’s historic contributions to maritime scholarship and the renewed urgency of ocean-related legal challenges. The collected contributions examine contemporary developments, including the implementation of the Agreement on Marine Biological Diversity of Areas Beyond National Jurisdiction, climate change and sea-level rise, maritime security, fisheries governance and human rights at sea. Together, they assess the continuing vitality of the United Nations Convention on the Law of the Sea as a ‘living treaty’ and interrogate its capacity to respond to shifting geopolitical, environmental and technological realities. Beyond charting doctrinal evolution, the Forum highlights the law of the sea’s systemic significance for the development of international law more broadly. It invites reflection on whether the traditional State-centric framework can sustain effective ocean governance in the face of accelerating global pressures.

Climate change resulting from human activity is causing sea-levels to rise. Rising sea-levels pose an existential threat to small islands. Some have argued that this might result in islands losing their status as ‘islands’ and, at the same time, their maritime areas. The present article disagrees. In order to qualify as an ‘island’, a coastal feature must be ‘a naturally formed area of land, surrounded by water, which is above water at high tide’: Article 121(1) of the United Nations Convention on the Law of the Sea (UNCLOS). A feature that meets these requirements is, according to Article 121(2), entitled to a territorial sea, an exclusive economic zone and a continental shelf. Article 121(3) provides that rocks which cannot sustain human habitation or an economic life of their own have no exclusive economic zone or continental shelf. The words ‘naturally formed area of land’, as well as broader considerations, suggest that the status of a feature is determined on the basis of its natural condition—not changes generated by human activity. Just as construction through human artifice cannot elevate a coastal feature into an island, man-made climate change which causes sea-level rise cannot turn an island into something other than what is described in Article 121(1).

Courts in England ordinarily grant anti-suit injunctions when proceedings are (or will soon be) initiated in a foreign court in breach of clauses which subject disputes to the exclusive jurisdiction of courts, or refer them to arbitration, in England. Would they, however, grant such relief in support of foreign dispute-resolution clauses? In UniCredit Bank v RusChemAlliance, the Supreme Court of the United Kingdom answered this question in the affirmative, thus expanding the English courts’ power to issue anti-suit injunctions. This article seeks to assess the likely extent of this expansion and the future implications it could have for the law on anti-suit injunctions in England. The article also examines the Supreme Court’s pronouncements on the other significant issue in the case concerning the law governing arbitration agreements and their potential effect following the enactment of the Arbitration Act 2025.

On 21 May 2024, the International Tribunal for the Law of the Sea (ITLOS) delivered its Advisory Opinion on Climate Change and International Law (Advisory Opinion) regarding the obligations of States Parties to the United Nations Convention on the Law of the Sea (UNCLOS) in respect of climate change. ITLOS made several methodological choices to answer the request for the Advisory Opinion, but none were more decisive than its extensive use of external rules and scientific materials to interpret both the questions presented and the relevant UNCLOS provisions. This article provides an account of the ways in which ITLOS engaged with legal and scientific external resources throughout its decision. The final section discusses some concerns raised by this interpretative approach, including unresolved questions related to the criteria for using external rules under the principle of systemic integration, and the justification for the role that scientific information plays in shaping the content of certain UNCLOS obligations as applied to climate change. These issues are important given the influence that the Advisory Opinion will have on future debates and negotiations, and because they are ultimately linked to the need for a sound theoretical foundation for using legal and non-legal external materials in treaty interpretation.

This article explores the law governing the nationality of ships in the context of the recent surge of the so-called ‘dark fleet’. Traditionally, international law governed the nationality of ships, inter alia, to ensure effective control by the flag State over its ships, a concern heightened by the rise of open registry States, which were supposedly unable to exercise effective control. Despite initial scepticism, the general acceptance of open registries as well as the fact that small States like the Marshall Islands can be responsible flag States have mitigated this concern. However, the emergence of ‘flags of deceit’ (FODs)—flag States consciously enabling the operation of dark ships—poses a different problem. In welcoming ‘fleets’ of ships that are poorly maintained, in breach of international maritime regulations or engaged in illicit activities, FODs are not simply unable but, rather, unwilling to exercise effective control over their vessels, threatening the public order at sea. This article argues that other States have the right to refuse to recognise FODs with a view to protecting their own rights from dark ships left adrift by their respective flag States through their unwillingness to exercise effective control.

The International Seabed Authority (ISA) is tasked with regulating deep seabed mining (DSM) in areas beyond national jurisdiction for the benefit of all humankind. Unlike most international institutions, the ISA operates as a frontline resource regulator with direct authority over DSM contracts and activities. To effectively carry out its regulatory mandate, the ISA operates under a complex institutional structure involving the delegation of significant powers to non-plenary bodies and administrative actors. As decision-making shifts to bodies less directly linked to State consent, it becomes increasingly important to ensure that these actors remain accountable both to the States granting them authority and to those affected by their decisions. This article argues that there is a mismatch between the ISA’s decision-making structure and its systems of administrative accountability that lead to a problem of affected interests being disregarded. The article highlights the structural and practical barriers that lead to this and then turns to an examination of the process mechanisms that the ISA has put in place to ensure that its decisions are responsive to affected interests. Whilst the ISA has some positive ad hoc procedures in place, it does not consistently institutionalise core administrative law pillars such as transparency, meaningful consultation, and the opportunity for review of decisions. A challenge for the ISA is to identify the range of accountability relationships created by the DSM regime, and to develop clear and consistent standards of accountability that can address the problem of disregard.

Maritime security challenges are intensifying globally, from armed attacks on shipping in the Red Sea to critical infrastructure sabotage and environmental threats from shadow fleets. These developments have led some to question whether the United Nations Convention on the Law of the Sea (UNCLOS) remains ‘fit for purpose’. This article reframes that debate, suggesting that maritime security operates through a complex assemblage of institutions and mechanisms. In this context, UNCLOS is best understood not as a monolithic ‘constitution’, but as one important site in a more complex and dynamic system of maritime security governance. It examines how the United Nations (UN) system, regional organisations and informal arrangements collectively address maritime security challenges, revealing both the strengths and limitations of this diverse governance landscape. The analysis shows that while this complexity enables flexible responses to varied challenges, it also creates coordination problems and accountability gaps. Rather than calling for a revision of UNCLOS, the article proposes three pathways for recalibrating the system: establishing a dedicated UN maritime security body; addressing interface conflicts through targeted interventions; and selectively formalising successful informal mechanisms.

Since Russian President Vladimir Putin announced his support for a plan to recruit fighters from abroad to join the Russian army in early 2022, foreigners have fought in Ukraine as part of Russian forces. Many of these fighters are mercenaries in the commonly understood sense of that term. That is, they are fighters who have gone, intentionally, to fight for Russia in return for significant payment. Although these fighters have often found themselves in Ukraine with little to no training and without their promised salaries, this article is not primarily concerned with them. Instead, it is interested in those fighters who arrived in Russia without knowing that they would be sent to the conflict, or who did not know that they were going to Russia at all. The article argues that such ‘forced fighters’ who are misled or tricked into taking part in an armed conflict should be given protection beyond that given to other combatants, specifically that they should be offered repatriation to their countries of origin. It argues that international humanitarian law is unable to effectively capture the position of these fighters or provide adequate protection to them. It suggests, rather, that the law on modern slavery can provide a way to understand and reconceptualise the position of these fighters—as victims of servitude and human trafficking—and that this body of law can deliver the remedy of repatriation to them.

This article contends that anthropogenic sea-level rise seriously undermines the exercise of self-determination by peoples living in Small Island Developing States (SIDS). Moreover, it argues that the effects of this would be severely exacerbated if the international community were to reject the possibility of statehood enduring notwithstanding total submergence, the complete loss of inhabitable land or the mass exodus of extant populations. In support of the claims made by several SIDS themselves, this article provides an analysis focused upon the relationship between the law of State continuity, on the one hand, and the peremptory norm of self-determination on the other. Ultimately, this analysis advances an understanding of State continuity and sea-level rise that favours existential resilience, making any future losses of statehood contingent upon voluntary dissolution by affected States.

In the aftermath of the adoption of the Implementing Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biodiversity in Areas Beyond National Jurisdiction (BBNJ Agreement) and in view of the global target to protect at least 30 per cent of the ocean by 2030 (30×30), an issue that merits attention is the surveillance of marine protected areas (MPAs) on the high seas. The BBNJ Agreement is remarkably silent on how the relevant management measures in future MPAs will be implemented, despite the fact that enforcement challenges are prevalent in existing MPAs. This article discusses the potential use of maritime domain awareness (MDA) tools, including earth observation tools like satellites, in ensuring effective surveillance and subsequent enforcement of high seas MPAs. The article first introduces the concept of MDA and the use of earth observation tools in that context, highlighting the advantages that such tools may have in ensuring compliance in MPAs. It then explores the legal framework governing the employment of earth observation tools in high seas MPAs. The article argues that States are not merely permitted but also obligated to monitor their vessels’ activities in high seas MPAs. Furthermore, States are under a general obligation of cooperation, including the obligation to share information that is obtained by MDA tools. Finally, the article briefly discusses how evidence, like satellite imagery, could be used for enforcement purposes, including before domestic courts. It concludes that the use of earth observation tools would be instrumental to the effective surveillance and enforcement of high seas MPAs.

This article uses the Sargasso Sea as a case study to provide an analysis of the provisions of Part III of the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ Agreement) on measures such as area-based management tools (ABMTs), including marine protected areas. The ability of the BBNJ Conference of the Parties (COP) to establish internationally legally binding ABMTs in areas beyond national jurisdiction (ABNJ) presents a new opportunity for the conservation of the Sargasso Sea. Existing work of the Sargasso Sea Commission, as well as the preparations it could make to support a proposal by one or more States Parties to the new COP for an ABMT in the Sargasso Sea are discussed, as is the comprehensive process the BBNJ Agreement establishes for stakeholder engagement as part of the submission of proposals. The Sargasso Sea Commission has a long history of collaboration with international organisations, governments, scientists and others to strengthen the stewardship of the Sargasso Sea. More recent activities to engage directly with the shipping industry stakeholder group specifically are discussed. Finally, the article discusses the work being undertaken in collecting the best available science, collaboration with other international frameworks and bodies and other stakeholders, and the preliminary work on the development of an outline management plan particularly in relation to ongoing monitoring using remote sensing capacity.

Law enforcement authorities (LEAs) increasingly need to obtain digital evidence that is stored or controlled across borders. As a result, States increasingly exercise enforcement jurisdiction extraterritorially by imposing investigative measures on service providers that possess or control data outside the territory, without the State’s LEAs physically entering another State’s territory. This exercise of ‘investigative jurisdiction’ seemingly conflicts with the longstanding prohibition of the exercise of extraterritorial enforcement jurisdiction in international law. This article argues that given the development of State practice, longstanding jurisdictional principles should adapt to global technologies. Consistent with the principle of comity, this article conceptualises a limited form of investigative jurisdiction that respects sovereignty and minimises conflicts of law.