It has been over 40 years since the United Nations Convention on the Law of the Sea (LOSC) was concluded and opened for signature, and 30 years since its entry into force. This has sparked renewed attention to the question of how the LOSC can continue to regulate new uses of, and threats to, our oceans. Some have sought to answer this question by framing the LOSC as a ‘constitution’ for the oceans, as a reassertion of its continued influence. This article shows that this provides a false sense of security. While the LOSC is one of the most impressive and significant treaties, it should not be regarded as a constitution. This article examines how the LOSC can remain an effective and enduring framework for the law of the sea, arguing that regarding it as a constitution does not necessarily contribute to that goal. Instead, it proposes a new approach to the treatment of the LOSC which attempts to explain how best it can serve as a ‘living treaty’ and as a framework that is truly capable of guiding legal responses to new opportunities and challenges at sea.

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.

Which international obligations are characterised as obligations owed erga omnes or erga omnes partes is today a crucial question for the enforcement of international law, particularly through adjudication before the International Court of Justice (ICJ). The ICJ, however, has not given sufficiently clear indication as to how it understands and identifies obligations erga omnes and erga omnes partes. This lack of clarity and consistency permits varied approaches to the articulation of such obligations, ultimately leaving uncertain the enforceability, through adjudication and otherwise, of a wide variety of obligations.

The common law tradition has always been sceptical of philosophy, prioritising the importance of practical experience in real world cases over abstract general ideas. This article attempts to demonstrate how the ideas of two philosophers—Fuller and Wittgenstein—help to explain the widespread use of the notion of purpose in real world case law. Fuller’s conception of law as the enterprise of subjecting human conduct to the governance of rules illuminates the common law’s respect for the agency of legal subjects, whether that be respecting parties’ purposes in making a contractual bargain or using purpose as a basis for limiting liability in tort. Similarly, Wittgenstein’s conception of language demonstrates the necessity of resort to purpose in interpretation, as the open-textured nature of words means that legal rules only become determinate when used in specific contexts for specific purposes. The article focuses primarily on the United Kingdom’s (UK) legal system, with its two tracks of the common law and parliamentary legislation, but also extends the argument to examples drawn from forms of supranational law to demonstrate that the analysis is capable of being generalised beyond the UK’s legal system.

In its Advisory Opinion on the Legal Consequences arising from the Policies and Practices of Israel in the Occupied Palestinian Territory, including East Jerusalem, the International Court of Justice (ICJ) ruled not only that Israeli policies and practices in the occupied territory systematically violated international law, but also that Israel’s ‘continued presence’ (i.e. occupation) as such had become illegal, so that Israel was required to withdraw from the Occupied Palestinian Territories as rapidly as possible. The ICJ’s finding that Israel engaged in a sustained abuse of its position as an occupying power, through annexation of territory and frustration of Palestinian self-determination, was central to its reasoning, as was its holding that the legality of the occupation was to be judged against the jus ad bellum. This article unpacks the concept of an illegal occupation. It argues that, as matter of the jus ad bellum, it is only the right to self-defence that could, in theory, justify Israel’s continued occupation. Curiously, however, the Opinion does not mention self-defence, although it preoccupied many of the judges writing separately. The article argues that two approaches to the occupation’s ad bellum illegality are most persuasive: first, that the occupation could not meet the necessity and proportionality criteria of lawful self-defence; and, second, that even a valid self-defence claim can be vitiated by a predominant ulterior purpose.

The 2025 International Court of Justice Advisory Opinion on Obligations of States in respect of Climate Change constitutes a diligent and reasoned exposition of the main bodies of international law on climate change. The Court read this law harmoniously and clearly identified States’ obligations as well as the legal consequences of breach. Under both treaty and customary international law, States must act with due diligence and do their utmost to mitigate climate change, including through action on fossil fuel production and consumption. The Court confirmed that the law of State responsibility applies if States fail to fulfil their obligations, and sketches a pathway for establishing causation of harm that would become relevant if reparation were sought.

This article examines the key dimensions of the Advisory Opinion, including the applicable law identified by the Court and its analysis of State responsibility, informing readers of the Court’s main findings and their consequences. It also puts forward a few reflections, including on the Advisory Opinion’s emphasis on international cooperation and finance flows, the Court’s views on sea-level rise and self-determination, the role of science in the Advisory Opinion and what the Court left for the future.

In the wake of Russia’s aggression against Ukraine, international lawyers and policy advisors are considering the tools that are available to third States that wish to respond to the serious breach of international law and support Ukraine. Within this context, the question of third-party countermeasures is once again highly relevant. Though the topic was contentious during the drafting of the Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA), doctrine on third-party countermeasures often argues that they are permissible under customary international law, even while acknowledging that opinio juris is lacking. Whereas it has been argued that this subjective requirement can be inferred, this article maintains that, given the ambiguity surrounding unilateral sanctions practice, it is necessary to demonstrate that States believe that they are legally permitted to adopt wrongful sanctions in response to a prior breach of an obligation erga omnes (partes). It is argued that the International Law Commission was right to not include third-party countermeasures in the final ARSIWA and that, while sanctions practice has seemingly flourished over the years, there has been little progress in conclusively establishing that third-party countermeasures are accepted as custom, as illustrated by the discussion on the confiscation of Russian State assets.

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.

The duty to render assistance to persons in distress is well established in the international law of the sea, but none of the instruments which codify the duty contains human rights obligations. However, serious human rights violations may occur during search and rescue (SAR) operations or because of the lack thereof. This article examines the duty of States to render assistance to persons in distress through the lens of international human rights law and advocates for a human rights-oriented approach to SAR. It discusses the due diligence nature of the duty, the scope of jurisdiction in maritime SAR and how States should act to adhere to their human rights obligations from the moment they receive a distress call through to the moment they disembark rescued persons on land.

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.

The widespread use of artificial intelligence technologies in border management throughout the European Union has significant human rights implications that extend beyond the commonly examined issues of privacy, non-discrimination and data protection. This article explores these overlooked impacts through three critical frameworks: the erosion of freedom of thought, the disempowerment of individuals and the politicization of human dignity. In uncovering these dynamics, the article argues for a broader conception of human rights to prevent their gradual erosion and safeguard the core principle of protecting human dignity.

This article argues that, in provisional measures cases, the International Court of Justice (ICJ) now examines jurisdiction by assessing not only an applicant’s arguments for jurisdiction, but also a respondent’s arguments against it. This more granular examination is different from the ICJ’s traditional prima facie test. The change in approach was demonstrated in the 2008 provisional measures order in Georgia v Russian Federation. This article suggests two likely explanations for the development of a more detailed test. The first is the ICJ’s reluctance to limit State sovereignty by imposing provisional measures since it held, in the 2001 LaGrand judgment, that they are binding. The second is the political sensitivity of the particular dispute. However, the more detailed approach to the question of jurisdiction in provisional measures has generated inconsistency in the ICJ’s jurisprudence: first, the malleability of this approach risks like cases being treated differently; second, this approach overlaps with the plausibility test, which concerns a separate requirement for provisional measures; and, third, this approach overlaps with the Oil Platforms test, which the Court uses to determine definitively whether it has jurisdiction ratione materiae. The new approach also promotes a dispute-settlement conception of the Court’s judicial function, rather than acknowledging its role in developing international law or maintaining public order.

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.

Alleged victims have often played a central role in litigation aimed at prompting climate change mitigation. Courts have identified such victims in order to grant plaintiffs standing to sue, justify their invocation of individual rights and consider claims for compensation. This article observes, however, that no individual can really be, at least in a strict legal sense, a victim of a State or an entity’s failure to mitigate climate change. This is because, while climate wrongs certainly harm society, they do not harm specific individuals in a sufficiently direct and proximate way. This observation has major implications for climate litigation, but it is not a fatal flaw: the absence of victims does not necessarily preclude litigation as, for instance, standing can often be established on sounder legal grounds.

This article explores the intersection of, and relationship between, the Biodiversity Beyond National Jurisdiction (BBNJ) Agreement and the Antarctic Treaty System (ATS). It examines the status of the Southern Ocean as an ‘area beyond national jurisdiction’ before analysing the application of the ‘not undermine’ principle to the ATS as developed in Article 5 BBNJ Agreement. The article examines the implications of the BBNJ Agreement in relation to environmental impact assessments, area-based protection, marine genetic resources and dispute resolution within the ATS. It argues that the thus far defensive approach of the Antarctic Treaty parties to the BBNJ Agreement is neither sustainable nor in the long-term interests of either agreement. It argues for positive engagement between the two regimes for the ultimate benefit of Southern Ocean governance.

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.

International investment law has long relied on treaties that grant enforceable rights to investors and resolve disputes through adjudication. This model has produced systemic constraints on regulatory autonomy, fragmented legal authority across treaty layers and limited responsiveness to development priorities. A new generation of treaties introduces a different organising logic. Investment facilitation agreements construct treaty obligations around procedural conduct rather than investor protection. Despite their growing prevalence, their legal structure, functional orientation and implications for treaty design remain under-theorised. This article argues that facilitation treaties reconstitute the legal function of investment agreements. They do not modify the protection-based model; they establish a procedural architecture in which treaty obligations operate through administrative performance at the domestic level. The argument is developed through comparative analysis of treaty practice at multiple levels, including the World Trade Organization Investment Facilitation for Development Agreement, the African Continental Free Trade Area Protocol on Investment, the Regional Comprehensive Economic Partnership and a range of second and third-generation bilateral treaties. Six procedural commitments (transparency, administrative coordination, investor support, dispute prevention, capacity-building and sustainability) are identified and theorised as foundational legal elements. The article contributes a general theory of procedural treaty design. It shows how legal ordering across international and domestic systems can be achieved through coordination rather than adjudication, with broader implications for international economic law and the evolution of international legal instruments.

The recent rise of ‘qualified neutrality’ has proven highly controversial. Some have suggested that the separation between the jus ad bellum and the jus in bello under international law may prevent the reform of ‘traditional neutrality’ into qualified neutrality. This article will seek to resolve academic debate on this topic, arguing that the principle of separation is of limited relevance to perpetuation and reform within the law of neutrality. Although the principle of separation is prima facie incompatible with qualified neutrality, it does not have the required characteristics as a legal rule to inhibit reform of the law of neutrality and the recognition of qualified neutrality as a positive rule under international law.

This article analyses whether Articles I and II of the Nuclear Non-Proliferation Treaty (NPT) permit nuclear sharing. It argues—contrary to previous research—that the ordinary meaning of Articles I and II, the NPT’s travaux préparatoires and subsequent agreements and practice point to a deep ambiguity as to whether nuclear sharing is permitted under these Articles. It then suggests that, while Articles I and II NPT offer little help in determining the legality of nuclear sharing, the nuclear disarmament obligation embedded in Article VI NPT can be used to challenge the legality of the practice.

Autonomous shipping is revolutionising the maritime industry. While scholarship has begun to explore the legal obstacles to the global operation of autonomous vessels under the existing legal framework, little attention has been paid to theoretical problems posed by law enforcement against those vessels under that framework. This article offers an account of law enforcement challenges posed by different categories of maritime autonomous surface ships as segmented by the key State actors’ enforcement powers (i.e. coastal and flag States) under the United Nations Convention on the Law of the Sea. The study concludes that a reconceptualisation of law enforcement vis-à-vis autonomous ships is required, reexamining the presumption of physicality. The article suggests that it is necessary to reevaluate the suitability of the ‘genuine link’ doctrine, shifting towards a shore-based Remote Operations Centre rule or devising international agreements that envisage dynamic or fluid enforcement mechanisms. This would necessitate a transition from the traditional view of jurisdiction based on person/object/flag of registration to a model of enforcement based on convenience.