This article examines how the war in Ukraine has had an impact upon the enlargement of the European Union (EU) and transnational cooperation in Europe. It explains how, in response to Russia's aggression against Ukraine, the EU has relaunched its enlargement process (notably, by opening accession negotiations with Ukraine), promoted the establishment of a new European Political Community and deepened its ties with other regional organisations, like the Council of Europe and the North Atlantic Treaty Organization, and the United Kingdom. It is argued that the return of large-scale warfare to the European continent for the first time since the end of World War II has contributed to reaffirming the role of the EU as a beacon of liberty, peace, security and prosperity, and highlighted the dynamism of the European integration project. Nevertheless, a number of challenges lie ahead, especially regarding enlargement, including both the candidates’ preparation and the EU's own readiness. The article therefore proceeds to map the debate about EU reform, the ongoing stalemate and the open questions concerning the future of Europe in order to illustrate fully the impact of the war in Ukraine on the enlargement project.

China frequently accuses Western governments of interfering in its domestic affairs. International lawyers might be inclined to dismiss these accusations as cynical misrepresentations of the doctrine of non-intervention. This article questions that view, drawing on Chinese State practice and recent Chinese literature. It argues that China propagates a new and distinctive approach to the doctrine of non-intervention, by which the doctrine changes depending on who is interfering with whom, in what context and for what purpose. This approach could also be increasingly useful to Western governments who seek to challenge pernicious forms of foreign influence over liberal democratic processes. Hence, Chinese and non-Chinese approaches to non-intervention might converge. This approach arguably reflects the concerns that originally animated the doctrine and is in line with ideas that have been advocated for by non-aligned States for at least 70 years. Whether this is a desirable development is another question. The article concludes with a critique of the new doctrine of non-intervention.

Whether an issue estoppel arises over foreign decisions on the governing law of the claim has not been directly considered by an English court, but decisions in other jurisdictions show that this question is increasingly being raised in litigation. Is there identity of issue if the two courts apply different choice of law rules? The answer turns on whether a broad or narrow framing of the issue is adopted. It is suggested that, absent an issue which is subject to forum international public policy, forum overriding mandatory rules or which is one that the forum court retains the prerogative to determine for itself, a broad framing ought to be adopted. Thus, in principle, an issue estoppel should arise over the identity of the governing law of the claim. However, issue estoppel should not operate where the choice of law category involved is underpinned by public policy considerations. The consideration of the specific issue of the governing law of the claim also feeds into broader questions on the applicability of issue estoppel whenever the two courts would apply different laws or frameworks to decide the issue. In general, whether a plea of issue estoppel ought to succeed depends on balancing the principles underlying res judicata against the considerations arising in each specific context.

Damage caused to underwater infrastructure has increased in frequency over the past few years. Incidents in the North Sea and the Baltic Sea have shown that anchor-dragging ships can easily cause disruption to internet or electrical networks, along with examples of other methods of deliberate harm, such as the use of explosives. The main legal challenges to the protection of critical offshore infrastructure lie outside the limits of the territorial sea. Relevant treaty law grants stronger legal protections to wrecks, unmanned platforms and floating buoys than to cross-border submarine telecommunications and power cables or gas and oil pipelines. Whilst the legal framework is fragmented and contains significant gaps, the United Nations Convention on the Law of the Sea permits coastal States to enforce their laws for the protection of submarine cables and pipelines outside the territorial sea. Based on the effects doctrine and the protective principle, coastal States can extend their criminal jurisdiction over deliberate damage to submarine cables and pipelines connected to their territory. Furthermore, recent incidents in Europe show that suspected stateless ships can be interdicted by the coastal State.

A key issue in the recognition and enforcement of foreign judgments is jurisdiction, with a distinction drawn between ‘direct’ jurisdictional rules, which are applied by the court of origin at the time of initial adjudication, and ‘indirect’ rules applied by a court at the recognition and enforcement stage. While some commentators and national laws suggest that no jurisdictional ‘gap’ should exist between direct and indirect rules, in this article it is contended that, outside the context of a federal system or international convention with uniform rules, no compelling justification exists for eliminating the gap.

This article analyses the role of comparative analysis in free movement judgments of the Court of Justice of the European Union (CJEU). It argues that comparative analysis plays an important role in how the CJEU decides the outcome of free movement cases and that free movement law should thus be characterised as a comparative law method. The argument is developed in three steps. First, comparative analysis takes place in all structural parts of free movement cases. It is not exclusively or even primarily limited to the proportionality test. Second, the role of comparative analysis is directly linked to the effective application of the free movement provisions. This means that comparative analysis is not only relied on to engage in standard-setting (‘calibration’) in free movement cases—it is also used to determine which cases should fall within the scope of application of the free movement provisions (‘demarcation’). Third, because of the close relationship between comparative analysis and the effective application of the free movement provisions, it is possible to characterise negative integration as a comparative law method. Although one component of this method is based on the traditional functional method in comparative law, the main comparative method in free movement law is closely linked to cosmopolitan pluralism, because negative integration provides a ‘frame’ or structure through which Member States are required to investigate and respond to the national laws of other Member States. This method can be described as ‘the law of differentiation’, because it identifies, analyses the extent and assesses the legitimacy of differences in national laws in the context of the internal market.

What are the philosophical and normative orientations of British international law scholarship during the Victorian era? This article explores and answers this question in three complementary steps. It begins with an analysis of the ‘public’ international law textbooks after 1830 to show that, instead of a single legal tradition, there coexisted three competing traditions during this period: a ‘naturalist’, an ‘historicist’ and a ‘voluntarist’ tradition. These three Victorian traditions will, in a second step, be studied in the context of ‘private’ international law—a discipline that developed and received its name during this period. A third section finally offers a detailed examination of the transformative work of Lassa Oppenheim, which straddled the Victorian nineteenth century and the ‘modern’ twentieth century. In revisiting the normative project(s) of Victorian international law, the article hopes to critique three prominent views in the contemporary academic literature. The first view holds that voluntarist State positivism exercised a dominant influence on British international law scholarship after 1830; a second view has claimed, relatedly, that during this period an idiosyncratic ‘English’ approach to international law emerged; and a third view has famously suggested that there was a ‘radical’ break in the discipline of international law around 1870.

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.

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.

Article 58 of the European Convention on Human Rights (ECHR) contains a provision which allows for the involuntary withdrawal, or expulsion, of a State from the ECHR if it has been expelled from, or ceased to be a member of, the Council of Europe (CoE). By comparing Russia's exit from the ECHR in 2022 with that of Greece in 1969, this article demonstrates that involuntary withdrawal poses a number of legal problems—partly as a result of it not having been considered during the drafting of the ECHR or the Statute of the CoE, and partly because of the highly unclear basis on which involuntary withdrawal operates. The article then conducts a comparative analysis of other regional human rights systems and public international law principles on treaty withdrawal in order to suggest a more comprehensive legal foundation for expulsion.

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.

The discourse on State immunity has traditionally focused on its application in judicial proceedings. However, in recent years scholars have begun to address whether the law on State immunity also protects foreign States against measures taken against their property by the territorial State's executive and/or legislative organs. This question has been raised following unilateral sanctions regimes freezing property of foreign States. It has gained renewed attention in the context of the ‘immobilization’ of around €300 billion of the Central Bank of Russia's assets as a reaction to the invasion of Ukraine by the Russian Federation. In addition, there are recent suggestions to subject these sovereign assets to further steps, including confiscation, the generation of investment returns or taxing windfall profits accruing to the entities holding the assets. This article revisits the various conceptions of the law on State immunity to address the question of whether a principle of State immunity against non-judicial measures of constraint exists. Based on a review of existing State practice and opinio juris, it argues that customary international law does provide for State immunity in this context. However, the article further contends that the content of the norm should be construed differently than in relation to judicial proceedings, recognizing the weight of public policy concerns of the territorial State.

The existence of international legal obligations which bind domestic non-State actors (DNSAs) is well-established throughout public international law, particularly in international criminal law and international humanitarian law. Yet the conceptual foundation of such obligations remains unclear—whilst the obligations of States and international organisations are rooted in the concept of consent, the international obligations of DNSAs are inherently non-consensual. There have been several attempts to explain the existence of DNSA obligations in particular areas of international law, but no account has provided a convincing general explanation. The unsettled conceptual basis of DNSA international obligations has given rise to controversy around their existence and legitimacy and whether it is desirable or possible to create international obligations for DNSAs in other areas, such as international human rights law. This article fills this gap by advancing a general account of the basis of the international obligations of DNSAs. The article builds on the most persuasive elements of existing accounts to argue that States have a capacity to impose international obligations on DNSAs which does not depend on any preexisting relationship or connection.

This article argues that the rule of contra proferentem is not applicable to international sales contracts governed by the United Nations Convention on Contracts for the International Sale of Goods (CISG). It further argues that the common recognition of the rule of contra proferentem under the CISG is an instance of a broader phenomenon which it calls ‘internationality overreach’. ‘Internationality overreach’ is the tendency to project onto the provisions of a uniform private law instrument doctrines and concepts which are inaccurately presumed to constitute universally recognised principles of private law or the ‘common core’ of various legal systems. This article demonstrates that internationality overreach disrupts the goals underpinning the harmonisation of commercial law in two ways: first, it undermines uniformity in the application of international conventions; and, second, it leads to outcomes that fall short of the agreement reached by the Contracting States during the drafting process. While this article focuses on the CISG, the argument developed in this article is of equal relevance to other uniform private law conventions which follow the principle of autonomous interpretation.

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.

International law has become a fixture before the courts of the United Kingdom (UK). But how is it actually used and how does this use relate to its means of reception into domestic law? Scholarship has tended to focus on how judges interpret and apply international law, to the exclusion of how it is deployed by litigants. In doing so, it also overlooks the relationship between the way an international norm is received into domestic law and its use in court. This article asks whether there are differences in the kinds of international law readily available to different litigants and how this plays out in the cut and thrust of domestic litigation—whether it is used as a sword or a shield, on the basis of domestic statute or the common law and what kinds of arguments are run in the absence of domestic footholds. This raises a broader point about the politics of statutory transposition, the practice of argument and the difficulties of litigating unincorporated international law.

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.

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.

While States can often refer to a single language text of a multilingual treaty, there are times when an examination of other language texts is required. This article proposes a novel three-step method for applying Article 33(4) of the Vienna Convention on the Law of Treaties to remove, or otherwise reconcile, differences in meaning between multilingual treaty texts. In doing so, this article seeks to address the current vacuum of practical guidance on when an examination of different authentic treaty texts is necessary in the process of interpretation, and how any differences in meaning between the texts should be removed or reconciled.

This article argues that critical and emerging technologies, evolving geopolitical dynamics and the urgent need to pursue the green agenda are changing the traditional approach of the European Union (EU) and its Member States towards their trade and security strategies, and this is particularly evident in the domain of export controls. In search of a balance between green energy, security and technological progress, this article explores the potential for a more cohesive and comprehensive regulatory framework for export controls at the EU level. It takes the debate beyond a technical level of export control lists to discuss geopolitical and strategic assumptions surrounding inter-State cooperation on the regulation of critical and emerging technologies and their components. The article underscores, in particular, the potential unintended repercussions of controls for the EU's technological future and the prospects of the green transition in Europe and beyond. Finally, it advocates for what is often overlooked in discussions: the necessity for the EU to set clear, long-term objectives for its export controls and to align them with the purposes and objectives of other EU economic instruments.