International Humanitarian Law Commons^™

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 …

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 …

The Special International Peace Zone: From History, Through Practice, Toward An End To Armed Conflict In Ukraine, Tom W. Bell

Notre Dame Journal of International & Comparative Law

This paper presents the special international peace zone as both an observed and ideal institution. Such a zone quells military conflict in an area over which sovereigns make conflicting territorial claims. It operates through an interim administration, governed by its own rules, independent of any single sovereign. Past examples include the Free City of Danzig (1920-39), the Free Territory of Trieste (1947-54), and United Nations Interim Administration Mission in Kosovo (1999-2008). Despite proven successes, these zones have suffered from an undue reliance on multi-national organizations—first the League of Nations and now the United Nations. Warring sovereigns seldom agree about the …

Volume 15, Issue 1 - Full Issue, Notre Dame Journal Of International & Comparative Law Volume 15

Notre Dame Journal of International & Comparative Law

No abstract provided.

Some Reflections On The Threshold For International Armed Conflict And On The Application Of The Law Of Armed Conflict In Any Armed Conflict, T.D. Gill

International Law Studies

This essay discusses the threshold of application of international humanitarian law (IHL) in both international (IAC) and non-international armed conflicts (NIAC). In relation to IAC it questions whether the International Committee of the Red Cross (ICRC) “first shot” approach is the most appropriate, since it opens the way for the intensification of conflicts beyond what is necessary in relation to relatively minor armed incidents and argues that the humanitarian protection clauses of IHL should be separated from the rules governing hostilities and makes a case for the application of ad bellum considerations of necessity and proportionality to act as a …

Targeting A Satellite: Contrasting Considerations Between The Jus Ad Bellum And The Jus In Bello, Hitoshi Nasu

International Law Studies

With the development and greater availability of counter-space capabilities, satellites are becoming a prime target of military threats. However, the legal assessment for the targeting of a satellite requires careful analysis because of its impacts on terrestrial activities and the potential to affect the rights and interests of third parties when their payloads are carried by the targeted satellite. With these two unique characteristics in mind, this article unravels the complexity of international legal regimes applicable to military operations conducted against a satellite by contrasting threshold legal considerations necessary for the identification and application of relevant legal requirements under the …

Cyber Peacekeeping Operations And The Regulation Of The Use Of Lethal Force, Nicholas Tsagourias, Giacomo Biggio

International Law Studies

Peacekeeping is an essential tool at the disposal of the United Nations for the maintenance of international peace and security. The growing relevance of cyber technologies presents itself as an opportunity to adapt peacekeeping to the challenges of a rapidly evolving security landscape. This article introduces the notion of "cyber-peacekeeping," defined as the incorporation and use of cyber capabilities by peacekeepers. It discusses the legal basis for cyber-peacekeeping and the foundational principles of consent, impartiality, and use of defensive force. The article examines the use of lethal force by cyber-peacekeepers under the law of armed conflict paradigm. It considers the …

Revisiting Ad Bellum Proportionality: Challenging The Factors Used To Assess It, Yishai Beer

International Law Studies

Traditionally, international law has established a binary distinction between jus ad bellum and jus in bello. The former relates to the right to exercise military force. The latter regulates the conduct of adversaries engaged in an armed conflict. However, the prevailing legal approach doesn't accept this dichotomy. It wants to reduce war's hazards by applying the ad bellum rules, including the proportionality requirement, continuously throughout the conduct of armed conflict. To that end, it has established factors that define the essence of the continuing ad bellum proportionality requirement. This article challenges the near-unanimous consensus regarding these factors. It argues that …

The Plea Of Necessity: An Oft Overlooked Response Option To Hostile Cyber Operations, Louise Arimatsu, Michael N. Schmitt

International Law Studies

States are increasingly focused on the measures—cyber or otherwise—that they can take in response to hostile cyber operations. Although cyber operations are usually responded to with acts of “retorsion” (acts that are lawful, although unfriendly), international law recognizes other self-help mechanisms that allow for more robust responses. In the cyber context, most attention has focused on countermeasures and self-defense. Yet, both are subject to various limitations that constrain their availability.

This article examines a further option, the so-called “plea of necessity.” It allows States to respond to a hostile cyber operation when the action taken would otherwise be unlawful but …

Application Of The Due Diligence Principle To Cyber Operations, Tomohiro Mikanagi

International Law Studies

The discreet use of proxies by States renders it difficult to prove attribution to States under the existing rules of attribution. On the other hand, the due diligence principle, if applicable, does not require attribution but can lead to the invocation of State responsibility for cyber operations emanating from the territory of other States. In the Corfu Channel judgment the ICJ recognized “every State’s obligation not to allow knowingly its territory to be used for acts contrary to the rights of other States,” and UN Member States agreed that existing international law applies to cyber operations. However, the UN Members …

Legal Advisers In The Field During Armed Conflict, Yoram Dinstein

International Law Studies

Additional Protocol I to the Geneva Conventions of 1949 requires that legal advisers be made available to military commanders, particularly during hostilities. This treaty stipulation was quite innovative in 1977, but it has achieved widespread implementation, even among non-Contracting Parties. It is noteworthy that the United States—which objects to numerous provisions of Additional Protocol I—does not dissent from the article requiring legal advisers. A study of the practice of States, made by the International Committee of the Red Cross, confirms that the norm requiring that legal advisers be made available to advise military commanders in time of armed conflict currently …

Military Action To Recover Occupied Land: Lawful Self-Defense Or Prohibited Use Of Force? The 2020 Nagorno-Karabakh Conflict Revisited, Tom Ruys, Felipe Rodriguez Silvestre

International Law Studies

In September 2020, heavy fighting erupted between Armenia and Azerbaijan in and around Nagorno-Karabakh, a region of Azerbaijan long controlled by Armenia. After two months of military confrontations, a tripartite ceasefire was concluded, drastically altering the pre-existing territorial status quo.

The "Second Nagorno-Karabakh War" brings to light a fundamental question for international law on the use of force—and one that has received limited attention in legal doctrine. The question is this: when part of a State’s territory is occupied by another State for an extended period of time, can the former still invoke the right of self-defense to justify …

Developing International Guidelines For Protecting Schools And Universities From Military Use During Armed Conflict, Steven Haines

International Law Studies

One consequence of armed conflict, especially that of a non-international character, is serious damage done to vital societal infrastructure. Education–schools and universities–can be severely disrupted, even subject to attack. Targeting of schools may not invariably be unlawful if educational facilities are being put to military use. Such use may itself not be unlawful but it can result in schools being transformed from civilian objects into military objectives–and subject, therefore, to lawful targeting. This was a problem highlighted by humanitarian NGOs a decade ago and led to the formation, by both NGOs and United Nations agencies, of the Global Coalition to …

Protection Of Data In Armed Conflict, Robin Geiss, Henning Lahmann

International Law Studies

This article presents a novel way to conceptualize the protection of data in situations of armed conflict. Although the question of the targeting of data through adversarial military cyber operations and its implications for the qualification of such conduct under International Humanitarian Law has been on scholars’ and states’ radar for the last few years, there remain a number of misunderstandings as to how to think about the notion of “data.” Based on a number of fictional scenarios, the article clarifies the pertinent terminology and makes some expedient distinctions between various types of data. It then analyzes how existing international …

Legal Reviews Of War Algorithms, Tobias Vestner, Altea Rossi

International Law Studies

States and scholars recognize legal reviews of weapons, means or methods of warfare as an essential tool to ensure the legality of military applications of artificial intelligence (AI). Yet, are existing practices fit for this task? This article identifies necessary adaptations to current practices. For AI-enabled systems that are used in relation to targeting, legal reviews need to assess the systems’ compliance with additional rules of international law, in particular targeting law under international humanitarian law (IHL). This article discusses the procedural ramifications thereof. The article further finds that AI systems’ predictability problem needs to be addressed by the technical …

Command Accountability For Ai Weapon Systems In The Law Of Armed Conflict, James Kraska

International Law Studies

The use of artificial intelligence (AI) in weapon systems enhances the ability of operational forces to fuse multispectral sensors to understand the warfighting environment, positively identify, track, and select targets, and engage them with the most appropriate effects. The potential for AI to help close the “kill chain” has raised concern that this creates a gap in accountability between the decisions of humans and the acts of machines, with humans no longer accountable for decisions made during armed conflict. This study suggests that there is no gap because the military commander is always directly and individually accountable for the employment …

Israel’S Perspective On Key Legal And Practical Issues Concerning The Application Of International Law To Cyber Operations, Roy Schöndorf

International Law Studies

The speech given by the Israeli Deputy Attorney General (International Law) at the Naval War College’s event on “Disruptive Technologies and International Law” sets out, for the first time, Israel’s position on the application of international law to cyber operations. Consistent with the position taken by the vast majority of States thus far, Israel considers that international law applies to such operations. The speech stresses that questions pertaining to the identification and application of relevant legal rules remain, given the profound differences between the cyber domain and traditional domains of warfare—land, sea, and air. Therefore, in Israel’s view, a cautious …

Armed Conflicts In Outer Space: Which Law Applies?, Frans G. Von Der Dunk

International Law Studies

So far, outer space has merely become involved in terrestrial armed conflicts as part of the supportive infrastructure for military activities. Unfortunately, the risk that this changes is considerably growing, and it can no longer be excluded that (armed) force will become used in outer space, either directed towards Earth or within outer space itself.

This raises serious issues in the legal context, where space law so far has been premised on the hope that armed conflicts in outer space could be avoided whereas the law of armed conflict was not required so far to deal with the use of …

Responding To Hostile Cyber Operations: The “In-Kind” Option, Michael N. Schmitt, Durward E. Johnson

International Law Studies

Facing hostile cyber operations, States are crafting responsive strategies, tactics and rules of engagement. One of the major challenges in doing so is that key aspects of the international law governing cyber responses are vague, unsettled or complex. Not surprisingly, therefore, international law is markedly absent from strategies and operational concepts. Rather, they tend to take on a practical “tit-for-tat” feel as policymakers logically view “in-kind” responses as “fair play.” For them, responding in-kind surely must be lawful notwithstanding any challenges in discerning the precise legal character of the initial hostile cyber operation.

Testing that sense, this article examines the …

The Human Dimension Of Peace And Aggression, Chiara Redaelli

International Law Studies

Since the adoption of the Charter of the United Nations, the current international legal framework has drastically changed. In its traditional understanding, aggression is “the supreme international crime” aimed at protecting sovereignty and the territorial integrity of states. On the other hand, the U.N. Charter endorses an understanding of peace in the negative sense, that is, as mere absence of war. As human rights have gained momentum, they have helped reshape the legal landscape, a phenomenon referred to as the humanization of international law. How do peace and aggression fit within the humanized legal framework? This article will investigate the …

The Interplay Of International Obligations Connected To The Conduct Of Others: Toward A Framework Of Mutual Compliance Among States Engaged In Partnered Warfare, Berenice Boutin

International Law Studies

This article examines international obligations that arise in relation to the conduct of other States, and analyzes how they apply and interact in the context of partnered warfare. It investigates rules of State responsibility relevant to the context of partnered warfare, as well as primary norms that impose obligations connected to the conduct of others. In essence, they consist of obligations not to actively help to or to blindly let others do what a State would not do itself. It is argued that, taken together, these rules form the contour of an overarching framework of mutual compliance among States cooperating …

Will Cyber Autonomy Undercut Democratic Accountability?, Ashley Deeks

International Law Studies

In recent years, legislative bodies such as the U.S. Congress and the U.K. Parliament have struggled to maintain a role for themselves in government decisions to conduct military operations against foreign adversaries. Some of these challenges arise from constitutional structures, but they are also due to the changing nature of conflict: a shift away from large-scale kinetic operations and toward smaller-scale operations—including cyber operations—that are less visible and that do not require robust legislative support. These modern operations leave legislatures to engage in ex post and sometimes ineffective efforts to hold their executive branches accountable for international uses of force …

Autonomous Cyber Capabilities Below And Above The Use Of Force Threshold: Balancing Proportionality And The Need For Speed, Peter Margulies

International Law Studies

Protecting the cyber domain requires speedy responses. Mustering that speed will be a task reserved for autonomous cyber agents—software that chooses particular actions without prior human approval. Unfortunately, autonomous agents also suffer from marked deficits, including bias, unintelligibility, and a lack of contextual judgment. Those deficits pose serious challenges for compliance with international law principles such as proportionality.

In the jus ad bellum, jus in bello, and the law of countermeasures, compliance with proportionality reduces harm and the risk of escalation. Autonomous agent flaws will impair their ability to make the fine-grained decisions that proportionality entails. However, a …