International Humanitarian Law Commons^™

An Exceptional Model At Sea: Functionalist Targeting And The Legal Vulnerability Of Maritime Civil Defense In Japan, Kentaro Furuya

International Law Studies

The intensifying security competition in East Asia, characterized by persistent territorial disputes and the potential for major regional contingencies, has placed the Japan Coast Guard (JCG) at a strategic crossroads. The 2023 Control Guideline, which outlines the JCG’s role during armed attacks, has further heightened interest in the agency’s legal status. This article examines the critical gap between Japan’s domestic legal framework and the international law of naval warfare, specifically addressing how the potential classification of JCG assets as military objectives undermines the safety of maritime civil defense operations.

While the Japanese government firmly maintains the JCG’s status as a …

International Law Situations: Internment Of Belligerent Forces, Raul (Pete) Pedrozo

International Law Studies

This Situation examines the duty of neutral States to detain belligerent warships, their officers, and crews during an international armed conflict. At the outset of the armed conflict between the United States and Iran, Iranian warships sought refuge in India and Sri Lanka following the sinking of the Iranian frigate IRIS Dena. India and Sri Lanka, as neutrals, have a duty to detain those warships and their officers and crews for the duration of the armed conflict and take appropriate measures to render the ships and their personnel incapable of taking to sea during the conflict.

International Law Situations: Humanitarian Corridors, Raul (Pete) Pedrozo

International Law Studies

This Situation examines the use of humanitarian corridors during an international armed conflict. While humanitarian corridors are not defined in international law, they have been used both on land and at sea to evacuate non-combatants, allow for the provision of humanitarian relief supplies, and provide for the safe passage of neutral shipping in areas of ongoing conflict.

What’S In A Name? Much Ado About “War-Sustaining” Objects, W. Casey Biggerstaff

International Law Studies

Recent conflicts have renewed the long-running debate over the legality of attacking economic objects under the law of armed conflict. Within that discourse, observers frequently frame the controversy in relation to an abstract U.S. “war-sustaining” position. Critics often characterize the United States as advancing a distinctive and overly permissive interpretation of military objectives that allegedly departs from the targeting criteria set forth in Article 52(2) of Additional Protocol I. This article challenges that characterization. It concludes that the United States does not apply a separate “war-sustaining” lex specialis to economic objects. Rather, U.S. practice reflects a contextual application of Article …

International Law Situations: Economic Warfare At Sea, Raul (Pete) Pedrozo

International Law Studies

This Situation examines what measures belligerents may take against enemy and neutral merchant ships at sea during an international armed conflict. Operation Epic Fury serves as the backdrop to demonstrate the applicability of economic warfare during international armed conflict at sea. Iranian-flagged and Guyanese-flagged vessels are operating in service of the Iranian economy and war effort. These ships may be captured as part of U.S. economic warfare against Iran.

International Law Situations: Blockade, Raul (Pete) Pedrozo

International Law Studies

This Situation examines the right of belligerents to establish and enforce a blockade and the right to conduct visit and search of enemy and neutral merchant ships globally outside neutral waters.

Battlefield Uncertainties And The Use Of Ai, Tsvetelina Van Benthem

International Law Studies

This article explores the relationship between uncertainty in armed conflict, the use of artificial intelligence (AI), and the content of international law. It first provides a review of different types of conflict-related uncertainty, both internal to the party to conflict and external, and considers the interaction between these existing uncertainties and the use of AI. In so doing, it also explores the new uncertainties that can be introduced through AI. Second, it analyzes national submissions on military uses of AI and autonomous weapons to outline the uncertainties raised by States and their relevance for regulatory approaches to the use of …

Technology-Based Challenges To The Law Applicable To Trade Interdiction During Armed Conflict At Sea: The Law Of Naval Warfare And Convoy Operations, Rob Mclaughlin

International Law Studies

The practice of convoy involves the concentration of a group of merchant vessels under the control and direction of warships and military aircraft for the purpose of protecting it from belligerent capture or attack. The practice has often been described as obsolete, but asserting the demise of the convoy has been as regular as it has been premature. It is fitting that this operational practice be subject to an updated legal treatment and identification of new legal challenges. This article seeks to reassess the law applicable to convoys based on the consequences of certain post-1945 technological developments. It notes that …

Closing The “Extreme Circumstances” Gap: The Legality Of Nuclear Weapons When The Survival Of A State Is In Question, Christopher J. Hart

International Law Studies

There is a gap at the heart of the law governing the use of nuclear weapons. Repeated threats by Russian leaders to use nuclear weapons against Ukraine highlight the urgency of closing this gap. This article reviews the central holding of the 1996 International Court of Justice advisory opinion on the Legality of the Threat or Use of Nuclear Weapons. The article focuses on the controversial “extreme circumstances” clause, in which the ICJ stated that it could not determine the legality of using nuclear weapons when the survival of a State was in question. This left open the questions …

“I Plead Ignorance”: Autonomous Weapons And Criminal Liability For Not Knowing The Knowable, Jonathan Kwik

International Law Studies

This article argues that the unpredictability and unintuitive behavior of modern artificial intelligence provide more opportunities for users of autonomous weapon systems (AWS) to remain ignorant of risks posed by their systems to protected entities on the battlefield, and that this ignorance can be maintained even in iterative situations featuring a prior civilian casualty event. It demonstrates this theorem through illustrative targeting scenarios, before formalizing the argument through a model showing the evolution of an AWS-user’s mens rea as they receive notice of a prior incident, and choose to pursue—or not pursue—an inquiry. This analysis reveals a perverse incentive structure, …

Modes Of Liability For Ai-Enabled Crimes In International Criminal Law, Antonio Coco

International Law Studies

As artificial intelligence (AI) technologies become increasingly embedded in human activity, the question of individual accountability for AI-enabled international crimes grows more pressing. This article examines how established doctrines of individual criminal responsibility under international criminal law—particularly the modes of liability recognized in the Statute of the International Criminal Court and in the jurisprudence of international criminal tribunals—may be applied to human actors who interact with AI systems in the commission of core international crimes. Through four hypothetical scenarios, the article explores varying forms of human involvement—from programming to deployment—and assesses whether existing modes of liability, such as perpetration, instigation, …

Ai-Enabled Decision-Support Systems In The Joint Targeting Cycle: Legal Challenges, Risks, And The Human(E) Dimension, Jessica Dorsey, Marta Bo

International Law Studies

Israel’s military campaign in Gaza as well as ongoing conflicts in Ukraine, Yemen, Iraq, and Syria include the reported military use of AI-enabled decision-support systems (AI-DSS) within the joint targeting cycle (JTC). These tools use AI techniques to collect and analyze data, provide information about the operational environment, and make actionable recommendations with the aim of aiding military decision-makers in evaluating factors relevant to legal compliance, such as taking precautions and ensuring proportionality in attacks. These systems are often touted as being simply a human aid and, as such, have flown largely under the radar regarding regulation as they are …

Legal Issues Arising From The Military Use Of Ai-Supported Biometrics, Marten Zwanenburg

International Law Studies

Biometrics is increasingly used by armed forces for a variety of purposes, such as access control, the registration of detainees, and increasingly also targeting. The capabilities of biometric systems are considerably strengthened when they are enabled by artificial intelligence (AI). This article analyzes legal questions that are raised by the military use of such AI-supported biometrics. It argues that relevant legal frameworks are International Humanitarian Law, international human rights law, and the right to privacy in particular, as well as data protection law. The article finds that arguably, IHL may require the use of (AI-supported) biometrics in certain situations if …

Ai And Naval Operations, Wolff Heintschel Von Heinegg

International Law Studies

Artificial intelligence systems in naval operations are reality. They enhance naval capabilities in various respects. Autonomous surface and underwater vehicles depend on such systems. Moreover, these systems contribute to threat detection and identification, to real-time strategy optimization, and to intelligence analysis. The present article provides a brief analysis of the legality of AI systems used by naval forces under the law of naval warfare, which, in many respects, differs considerably from the law of land warfare. Accordingly, it is necessary to distinguish between attacks from the sea against targets on land and attacks against targets at sea and in the …

Military Ai And The Specter Of The Limitless War, Yuval Shany, Yahli Shereshevsky

International Law Studies

Legal and extra-legal factors related to the development of international humanitarian law (IHL) support the exercise of strategic restraint during armed conflicts. We claim, however, that technological developments in the area of military artificial intelligence (AI) fundamentally do away with many of the technological constraints that limited the capacity of militaries to fully utilize the “license to kill” afforded to them by IHL. Such a violence-enhancing effect can become even more dramatic in cases where other restraining factors are less effective. The upshot of our analysis is that the implicit assumption that IHL would be applied in a context of …

Symposium—Introduction, Russell Buchan

International Law Studies

In March 2025 the University of Reading and the U.S. Naval War College convened a workshop at the University of Reading in the United Kingdom to examine the application of the jus ad bellum, jus in bello, and international criminal law to the use of military AI. This is the introduction to the symposium, published as Volume 107 of International Law Studies.

Artificial Intelligence And The “Armed Attack” Threshold In International Law, Katie A. Johnston

International Law Studies

This article argues that the deployment of artificial intelligence, even in its strong fully autonomous form, does not have significant consequences for the application of the jus ad bellum framework, and in particular the armed attack threshold. As with all new weapons technologies, the deployment of artificial intelligence in the resort to force requires consideration of what “imminence” means in this context. However, artificial intelligence is fundamentally a means of making decisions to resort to force or contributing to the reasons for which such decisions are made by humans. Unlike the jus in bello, the jus ad bellum is …

Classification Of The Armed Conflicts In The Near East, Marco Sassòli

International Law Studies

This article explores the proper classification of Israel’s current conflicts with Hamas and Hezbollah as international or non-international armed conflicts. It discusses the different possibilities of how the international humanitarian law of international or non-international armed conflict applies to those conflicts and whether and to what extent the international humanitarian law of military occupation applies to the conduct of Israel Defence Forces in the Gaza Strip and Lebanon. It also explains why the proper classification of the conflicts still matters and is not only an intellectual exercise for scholars or students. While every conflict has its specifics, the article deals …

Ai Enabled Autonomous Weapons And Human Control: Part Iii: Human Control And System Operators, Lena Trabucco

International Law Studies

This article is the third installment of a three-part series on AI-enabled weapons and human control. Artificial intelligence (AI) is shaping debates about military technology by challenging the role of human decision-making in the use of autonomous weapon systems (AWS). This article argues that effective governance of AI-enabled AWS requires moving beyond narrow conceptions of “meaningful human control” and instead recognizing a network of embedded human judgment throughout the weapon system’s lifecycle. This article focuses on the operator stage, examining the unique role of operators through guiding, observing, and terminating deployed AWS. Drawing on policy debates, doctrinal frameworks, and empirical …

Ai-Enabled Autonomous Weapons And Human Control: Part Ii: Human Control And Military Commanders, Lena Trabucco

International Law Studies

This article is the second installment of a three-part series exploring human control throughout the entire life cycle of an autonomous weapon system (AWS). The series aims to understand the decision-making process and identify key decision-makers to see how human judgment is embedded into an AWS's parameters. Each article in this series focuses on a different stage of the life cycle. The first article discussed the roles and responsibilities of software developers and designers during the design and development phase. This article looks at the role of commanders in decision-making related to AWS deployment. The third article in the series …

Ai-Enabled Autonomous Weapons And Human Control: Part I: Human Control And Machine Learning Design And Development, Lena Trabucco

International Law Studies

At the center of the emergence of artificial intelligence (AI) and autonomous weapon systems (AWS) is the challenge of human control. AI has the potential to reshape the boundaries of military capabilities. In particular, the increasing sophistication of AWS necessitates a deep examination of the balance between machine autonomy and the role and requirements of human decision-makers. In pursuit of this balance, the concept of meaningful human control emerged. It is a concept born of necessity and offers a platform to reexamine and redefine the scope of human involvement in critical and time-sensitive decision-making. MHC has become a defining feature …

Proportionality: Can’T Live With It But Can’T Live Without It, Geoffrey S. Corn

International Law Studies

Perhaps no other word in the international humanitarian law lexicon evokes more interest and emotion than proportionality. How States implement the rule of proportionality is perhaps the most hotly debated aspect of international humanitarian law. The indeterminate nature of the rule allows for its meaning to conform to whatever its reader wants it to mean. This is a consequence of the variables related to key provisions of the rule: How do we assess military advantage? What makes an anticipated military advantage “concrete and direct”? And most problematic of all, what is the meaning of the term “excessive”? All of these …

Artificial Intelligence And Autonomous Systems In Warfighting At Sea, Nicholas Kadlec

International Law Studies

Much of the debate surrounding the military use of artificial intelligence (AI) tends to focus on lethal autonomous weapons systems. Those are systems that, once activated, can select and engage targets without further human intervention; sometimes pejoratively called “killer robots.” Moreover, debates often focus on their use and risks in land warfare. This land-warfare focus tends to invoke questions about the systems’ ability to distinguish between combatants and civilians on urban battlefields and the potential for mistakes. Legal debates about the lawfulness of AI and lethal autonomous weapons systems in warfare similarly tend to focus on land warfare and thus …

Newport Manual On The Law Of Naval Warfare, Second Edition, Newport Manual Expert Group

International Law Studies

The Newport Manual on the Law of Naval Warfare, Second Edition, is a continuing effort to restate the law of naval warfare as a purely lex lata exercise. Like the first edition of 2023, it is designed to provide a practical guide for commanders and seafarers, lawyers and officials, and educators and students. In doing so, the Manual includes developments in warfighting technologies in recent decades, which have significantly influenced the nature of war at sea. This second edition has been edited by four of the original authors following an extensive review and revision process.

The Obligation Of “Due Regard” In The Eez During Armed Conflict At Sea, James Kraska

International Law Studies

This article explores the rights of belligerent warships and military aircraft to engage in hostile operations within a neutral coastal State’s exclusive economic zone (EEZ) during armed conflict. It argues that peacetime rules of due regard for coastal State sovereign rights and jurisdiction do not constrain these operations. The United Nations Convention on the Law of the Sea (UNCLOS) established the peacetime obligation of due regard in the EEZ. By 1984, the EEZ had become customary international law binding on all States. The San Remo Manual on International Law Applicable to Armed Conflict at Sea suggests belligerent naval forces owe …

Sunk In Battle, But The War Is Not Over: Who Owns The Moskva?, Caroline Tuckett

International Law Studies

The study of underwater cultural heritage, and that of sunken warships, has typically focused on the legal protections that surround a site in the years, or often centuries, after the sinking. The Russia-Ukraine conflict has given cause to study the topic in a more modern context. Several Russian Naval vessels have been sunk by Ukraine, the most famous being the Black Sea flagship, the Moskva, in April 2022. Following the sinking, Ukraine stated the Moskva was now a heritage site, with a Ukrainian Defence Minister joking that the wreck was simply “one more diving spot.”

This article will examine …

Unclos And The Law Of Occupation: On The Rights And Duties Of Occupying States In Maritime Areas, Louis Mcdonough Monroy

International Law Studies

As of today, the framework of ocean governance of coastal maritime areas created by the United Nations Convention on the Law of the Sea (UNCLOS) is well understood and accepted by the international community. However, there are large and important areas of ocean space around the world that are subject to a more nuanced framework of interrelated norms. These are maritime areas that have come under the effective control of occupying States, often through the use of force. As such, the legal framework applicable to these maritime areas is that of the law of occupation. Nevertheless, because of the specificities …

Annotated Supplement To The Commander's Handbook On The Law Of Naval Operations

International Law Studies

The Commander’s Handbook on the Law of Naval Operations is used in the United States and throughout the world as a restatement of U.S. doctrinal law positions on matters affecting the operations of the U.S. Navy, the U.S. Marine Corps, and the U.S. Coast Guard. Judge advocates and legal advisers have occasion to conduct deeper research to identify the context and source of the rules reflected in the Commander’s Handbook. Responding to this need, an Annotated Supplement to The Commander’s Handbook was produced in 1997 and published as volume 73 of International Law Studies. In the intervening decades, …

Chapter 4: Safeguarding U.S. National Interests In The Maritime Environment

International Law Studies

The Commander’s Handbook on the Law of Naval Operations is used in the United States and throughout the world as a restatement of U.S. doctrinal law positions on matters affecting the operations of the U.S. Navy, the U.S. Marine Corps, and the U.S. Coast Guard. Judge advocates and legal advisers have occasion to conduct deeper research to identify the context and source of the rules reflected in the Commander’s Handbook. Responding to this need, an Annotated Supplement to The Commander’s Handbook was produced in 1997 and published as volume 73 of International Law Studies. In the intervening decades, …

Chapter 1: Legal Divisions Of The Oceans And Airspace

International Law Studies

The Commander’s Handbook on the Law of Naval Operations is used in the United States and throughout the world as a restatement of U.S. doctrinal law positions on matters affecting the operations of the U.S. Navy, the U.S. Marine Corps, and the U.S. Coast Guard. Judge advocates and legal advisers have occasion to conduct deeper research to identify the context and source of the rules reflected in the Commander’s Handbook. Responding to this need, an Annotated Supplement to The Commander’s Handbook was produced in 1997 and published as volume 73 of International Law Studies. In the intervening decades, …