ChatGPT launched in November 2022, triggering a global debate on the use of artificial intelligence (AI). A debate on AI-enabled lethal autonomous weapon systems (LAWS) has been underway far longer. Two sides have emerged: one in favor and one opposed to an international law ban on LAWS. This essay explains the position of advocates of a ban without attempting to persuade opponents. Supporters of a ban believe LAWS are already unlawful and immoral to use without the need of a new treaty or protocol. They nevertheless seek an express prohibition to educate and publicize the threats these weapons pose. Foremost among their concerns is the “black box” problem. Programmers cannot know what a computer operating a weapons system empowered with AI will “learn” from the algorithm they use. They cannot know at the time of deployment if the system will comply with the prohibition on the use of force or the human right to life that applies in both war and peace. Even if they could, mechanized killing affronts human dignity. Ban supporters have long known that “AI models are not safe and no one knows how to reliably make them safe” or morally acceptable in taking human life.

Protected areas safeguard biodiversity of global ecological importance, even throughout armed conflicts. The International Law Commission's Principles on Protection of the Environment in Relation to Armed Conflicts propose that certain ecologically important areas could be designated as protected zones during armed conflicts. This article uses a geospatial analysis of armed conflicts and Key Biodiversity Areas and three case studies to inform recommendations on how the protection of ecologically important areas could be enhanced through visibility, local actors and international stakeholders as part of a broader interpretation of a protected zone.

In this iteration of the Review's “Beyond the Literature” series, we have invited Ezequiel Heffes to introduce his recent book Detention by Non-State Armed Groups under International Law, before then posing a series of questions to Tilman Rodenhäuser, René Provost, Mariana Chacón Lozano and Katharine Fortin, who have agreed to serve as discussants of the book. Tilman Rodenhäuser is a Legal Adviser at the International Committee of the Red Cross (ICRC), with particular expertise in non-State armed groups (NSAGs) and detention. René Provost is the James McGill Professor of Law at McGill University and has written extensively on public international law, including his recent monograph Rebel Courts: The Administration of Justice by Armed Insurgents.1 Mariana Chacón Lozano has served as the Operational Legal Coordinator for the ICRC in Colombia since October 2020 and has worked for the ICRC since 2011. Katharine Fortin is Associate Professor at the Netherlands Institute of Human Rights within the Faculty of Law, Economics and Governance of Utrecht University. The Review team is grateful to all four discussants, and to Ezequiel, for taking part in this engaging conversation.

This article outlines and evaluates the US perspective on how treaty and customary international law protect the natural environment during international armed conflict. It surveys the relevant treaties to which the United States is a party and examines US views on their pertinent provisions. It then assesses claims that the environmental obligations residing in the 1977 Additional Protocol I to the 1949 Geneva Conventions have attained customary status, outlines the United States’ rejection of those claims, and evaluates the reasonableness thereof. Finally, it highlights ambiguities in certain US environmental positions, the resolution of which would bring much-needed clarity to the law.

In 2020, the International Committee of the Red Cross's work on the protection of the natural environment under international humanitarian law (IHL) produced the Committee's Guidelines on the Protection of the Natural Environment in Armed Conflict (ICRC Guidelines), an update of their 1994 predecessor. The ICRC Guidelines consist of thirty-two rules and recommendations under IHL, each accompanied by a commentary explaining their legal basis and providing guidance for interpretation. This article presents an overview of the context surrounding the Guidelines, certain key legal content, and practical implications for the conduct of parties to armed conflict as they fight.

Dr Marja Lehto is Ambassador for International Legal Affairs at the Ministry for Foreign Affairs of Finland, and Adjunct Professor of International Law at the University of Helsinki. She was a member of the United Nations (UN) International Law Commission (ILC) and served as the Special Rapporteur for the topic “Protection of the Environment in Relation to Armed Conflicts” from 2017 to 2022. Dr Lehto is also a member of the Council of the International Institute of Humanitarian Law since 2019. She has formerly served, inter alia, as Legal Adviser to the Finnish UN Mission in New York (1995–2000), as Head of the Unit for Public International Law (2000–09), and as Finland's Ambassador to Luxembourg (2009–14). For most of her career, she has worked on issues related to international peace and security, including international criminal justice and international humanitarian law (IHL), and she has published on a broad range of international legal questions related to the law of the sea, international environmental law (IEL), State succession, use of force, armed conflicts, terrorism and cyber security.

On its seventy-fifth anniversary last year, the Nuremberg war crime trials moved again into the spotlight of public attention. To the present day, Nuremberg is mainly portrayed as the birth of international criminal law being the first tribunal that held individuals accountable for war crimes committed during the Second World War. As we argue in this article, there is an often-overseen dark legacy of Nuremberg as it represents an unused opportunity to establish accountability for inhumane military practices, especially in air warfare, being of tragic influence for the postwar development of International Humanitarian Law (IHL) as a whole. Going beyond the existing criticism already voiced on Nuremberg’s shortcomings, we hold that the Tribunal’s reluctance to prosecute bombing practices sowed the seeds for the decay of IHL by creating institutionalized silences, especially for massive violations of the principle of distinction. The tribunal thereby sidelined pre-war IHL and infected the development of post-war IHL by retroactively legitimating the bombing practices of the Axis powers and at least indirectly of the Allies. We argue that the failure to prosecute ‘total war’-practices and reestablish former restrictive legal structures regarding aerial bombardment has fundamentally eroded the pre-war meaning of the principle of distinction leading to its downfall in the First Additional Protocol to the Geneva Convention of 1977. We describe these developments as a form of judicial desuetudo, meaning the abrogation of a rule through its subsequent non-enforcement by an international court during and after massive law violations because of perceived or real political constraints.

In its updated Commentaries on the 1949 Geneva Conventions, the International Committee of the Red Cross (ICRC) embraces the ‘external’ interpretation of Article 1 common to the four Geneva Conventions, according to which States have certain negative (complicity-type) and positive (prevention/response) obligations to ‘ensure respect’ for the Conventions by other actors. This interpretation has been gaining support since the 1960s, though the ICRC's new Commentaries have served as a catalyst for some States recently to express contrary views. This article focuses on two major methodological shortcomings in the existing literature, offering a much firmer foundation for the external obligation under common Article 1. First, it demonstrates the overwhelming support in subsequent practice for external obligations. Previous studies have failed to explain the method by which this practice is taken into account, given the existence of some inconsistent practice. This article addresses this general question of treaty interpretation, critiquing the approach of the International Law Commission that relegates majority practice to supplementary means of interpretation and proposing instead a principled approach that better fits and justifies the judicial practice here. Secondly, the article challenges two common assumptions about the travaux: first, that an original, restrictive meaning was intended, and secondly that the travaux of Additional Protocol I offer no support for external obligations. Given the ubiquity of military assistance and partnering, these findings have far-reaching consequences for the liability of States.

The traditional effective control test for determining the existence of a belligerent occupation requires boots on the ground. However, the evolution of the international law of occupation and the emergence of complex situations, particularly of a technological nature, necessitate a functional approach that protects the rights of occupied populations. The political, historical and geographical conditions of Gaza allow Israel to exert effective remote control. Despite the disengagement of Israel from Gaza in 2005 and the assumption of military and political authority by Hamas, this article argues that Israel nonetheless continues to be in effective occupation of the Gaza Strip on the basis of the following grounds: (1) the relatively small size of Gaza in connection with the technological superiority of the Israeli air force allows Israeli boots to be present in Gaza within a reasonable response time; (2) Hamas's authority and armed resistance do not impede the status of occupation; (3) the long pre-disengagement occupation and close proximity between Israel and Gaza (geography) allow for the remote exercise of effective control; and (4) all imports, exports in and out of Gaza, and any movement of persons are fully controlled and regulated by Israel.

Many contemporary armed conflicts are shaped by the reliance on airstrikes using traditional fighter planes or remotely piloted drones. As accounts of civilian casualties from airstrikes abound, the ethics and legality of individual airstrikes and broader targeting practices remain contested. Yet these concerns and debates are not new. In fact, a key attempt to regulate aerial warfare was made 100 years ago. In this article, we approach the regulation of aerial warfare through an examination of the 1923 Hague Draft Rules of Aerial Warfare and the contemporary scholarly discussion of these rules. While the Draft Rules have never been converted into a treaty, they embody logics of thinking about civilians, technologies of aerial warfare, and targeting that are still resonating in contemporary discussions of aerial warfare. This article argues for a contextualized understanding of the Draft Rules as an attempt to adapt International Humanitarian Law (IHL) to the new technological realities while maintaining distinctions between different kinds of spaces and non-combatants. We argue that the Draft Rules prefigure later debates about the legality of aerial bombing by tacitly operating with a narrow understanding of the civilian and by offering a range of excuses and justifications for bombing civilians.

The protection of the environment during warfare attracted significant attention in the 1990s, especially after the 1990–91 Gulf War. It became clear at that time that the few rules provided by international humanitarian law (IHL) aimed specifically at protecting the environment were insufficient. Various studies have since been undertaken with the aim of strengthening that protection from an IHL perspective. It is only recently that scholars and institutions like the International Law Commission have started to reflect on how to better protect the environment in armed conflict through the lens of another branch of international law, namely, international environmental law (IEL). Such an approach has involved examining the interplay between IHL and IEL, and scholars have subsequently proposed and then elaborated on frameworks in that respect. This paper intends to identify common trends of those frameworks and to critically appraise them, with the aim of providing a suitable approach to the interplay between IHL and IEL.

Actors engaging in a diverse set of environmental protection activities are experiencing serious difficulties executing their mandates during armed conflict, leading to environmental harm that could otherwise have been mitigated. This article examines to what extent the international legal and policy framework can ensure the protection of environmental protection actors during armed conflict. It is argued that environmental protection actors can be seen either as part of civil defence organizations or as humanitarian relief actors, and are therefore covered by special protections under international humanitarian law. However, two main challenges remain: (1) despite these existing provisions, environmental protection actors may still face access and safety issues during armed conflict, and (2) within this framework, environmental protection activities must be linked to civilian needs and cannot be conducted based on ecocentric motivations. To overcome these challenges, the article introduces the concept of “environmentarian corridors”. Environmentarian corridors would allow for the unimpeded movement of environmental protection workers and resources through contested territory and into emergency areas to protect the environment. They would also serve to increase awareness about obligations to protect the environment and would help to ensure the safety of environmental protection actors during armed conflict, as the role and mandate of these actors is explicitly accepted by stakeholders. Additionally, environmentarian corridors offer potential for conducting environmental protection activities on ecocentric grounds. The article concludes by advocating for stakeholders to employ the provisions and concepts articulated herein as a means to further promote and strengthen initiatives aimed at protecting the environment during armed conflict.

Given the increasing size and functions of United Nations (UN) peace operations (POs) and the fact that they often operate in contexts where natural resources are degraded, POs have repercussions on the environment. Yet, there is not much literature on their obligations regarding the protection of the environment in relation to armed conflicts. This article provides insights into the obligations of POs in relation to armed conflict. First, it highlights POs’ customary international environmental law obligations. Second, it delves into their environmental obligations under the UN's internal rules and the host State's laws. Third, it explores obligations that arise from their mandates. In each of these sections, the article highlights the relevance and application of these obligations in armed conflicts. The last section examines the obligations of POs to protect the natural environment under international humanitarian law.