Military Use of Biometrics Series – Introduction
On 7-8 May 2024, a conference brought together a group of scholars and practitioners to discuss the law applicable to the use of biometrics by armed forces. The conference, which took place in Tallinn, Estonia, was organized by the War Studies Research Centre (WSRC) of the Netherlands Defence Academy, the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE), and the Amsterdam Center for International Law (ACIL). The conference followed a workshop on the same topic held in May 2023 in Amsterdam.
This series includes three posts based on presentations given at the conference, and subsequently published as a symposium in the Journal of International Humanitarian Legal Studies (JIHLS). These articles are available open access.
Biometrics and the Armed Forces
“Biometrics” is the automated recognition of individuals based on their biological and behavioural characteristics. A well-known example is facial recognition technology. Biometrics are widely used for civilian and commercial purposes but are also increasingly being adopted by armed forces for a variety of purposes, from access control to military compounds to the targeting of enemy personnel. Increasingly, this is combined with the use of artificial intelligence (AI), such as Israel’s reported use of the “Lavender” system in Gaza.
Currently, armed forces increasingly recognize the utility of biometrics as a capability. A limited but mounting number of militaries make use of biometrics, in most cases for a specific set of purposes. As a consequence, only a small body of scholarship has focused on the military use of biometrics, although this body is growing. Yet, the military use of biometrics acts as a window to broader themes and questions concerning the use of (digital) data by armed forces in a broad range of situations, ranging from peacetime to armed conflict. The posts in this series provide a good example.
The Series
In the first post, Lily Hamourtziadou and Welmoet Wels focus on biometrics of the dead.
They refer to this as necrometrics to distinguish it from biometrics taken from the living. The authors explain that there are certain peculiarities of necrometrics, in particular due to the fact that dead bodies decompose. They link their discussion of necrometrics to a number of broader themes.
First, they explain that international humanitarian law (IHL) includes a number of obligations that require parties to an armed conflict to identify those killed during an armed conflict. Biometrics may contribute to such identification, and they argue that States that have the technology and ability to deploy necrometric methods should do so to fulfil these obligations. They then take a broader perspective, arguing that the meticulous recording of casualties enables us to understand suffering and loss, as well as the impact of armed conflict on individuals and communities. They highlight a few initiatives that are trying to achieve this, including the Iraqi Body Count.
Another theme their contribution touches is the link between necrometrics and human security, an approach that has been embraced by NATO. This approach provides an understanding of conflict and crisis that allows NATO to develop a more comprehensive view of the human environment, to centre on people, and address the differentiated impacts of conflict and crisis on different parts of a population. Finally, they suggest that necrometrics can contribute to remembrance and memorialisation as well as achieving justice.
Emelie Andersin investigates the use of facial recognition technology (FRT), which can be used as input for AI-enabled decision support systems (AI DSS) for identifying human targets based on their visual characteristics. She takes the reported use of AI-enabled FRT by Israel in the conflict in Gaza as an example, first describing reports on the use of the “Lavender” and “Where’s Daddy” systems by the Israel Defence Forces (IDF). Such systems are reported to make use of biometric data gathered through an extensive use of FRT in Gaza, leading checkpoints to become areas of involuntary biometric collection.
The author focuses on some of the technical risks of the use of FRT, in particular the risk of false positives, i.e. a positive match that is incorrect. This risk, she contends, is aggravated by the problem of algorithmic bias of AI systems and shifting definitions leading to an expansive definition of who is a legitimate target and thus a “match.” She then turns her attention back to the way in which Israel collects biometric data in Gaza, arguing that this raises legal concerns under IHL, arguably violating a number of obligations under the Third and Fourth Geneva Conventions. Finally, she discusses legal concerns arising from the use of FRT for the purposes of targeting, arising from the principles of distinction and proportionality. She concludes that despite some claims that AI DSS and FRT will improve respect for IHL and limit casualties, they may actually entrench civilian harm.
The conclusion that biometrics may exacerbate civilian harm is shared by Anna Greipl. Her post examines the link between biometrics and persons with disabilities in armed conflict. She explains that biometric systems are constructed based on implicit assumptions about what a “normal” human body looks like and how it behaves; these do not adequately take the situation of persons with disabilities into account. For example, when data used to train an algorithm does not include sufficient examples of a particular disability, the system will perceive them as an outlier with associated risks for persons with that disability.
To counter such risks, the author advocates for an inclusive approach to biometric systems on at least two levels. First, biometric systems should be built to follow a disability-inclusive framework, for example by involving persons with disabilities in such development. Second, non-technical measures are also necessary. These encompass changes in doctrine, training, and budgeting. Through the implementation of these measures, armed forces may utilize biometric technology to improve operational effectiveness while minimizing harm to all civilians in armed conflicts. She concludes that by incorporating a disability-inclusive perspective into the development and military deployment of biometric systems, we can transform these systems from new sources of risk into genuine means of protection.
Conclusion
The three posts showcase not only some of the ways in which biometric systems can add value to military operations, but also that their use raises a variety of legal questions. The posts in this series suggest possible ways to approach these questions but do not offer definitive answers. As the use of biometrics becomes increasingly entrenched among militaries, there is fertile ground for further research. A possibility for further discussion will be offered by the third conference on the law applicable to the use of biometrics by armed forces, which will take place on 23–24 October 2025 in Tallinn.
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Marten Zwanenburg is Professor of Military Law at the University of Amsterdam and at the Faculty of Military Sciences of the Netherlands Defence Academy. He has previously worked as a legal counsel for the ministries of Defence and Foreign Affairs of the Netherlands.
Dr Aleksi Kajander is a researcher at the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) and the Tallinn University of Technology’s Department of Law.
Major Steven van de Put is a Legal Advisor in the Royal Netherlands Air Force.
The views expressed are those of the authors, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.
Articles of War is a forum for professionals to share opinions and cultivate ideas. Articles of War does not screen articles to fit a particular editorial agenda, nor endorse or advocate material that is published. Authorship does not indicate affiliation with Articles of War, the Lieber Institute, or the United States Military Academy West Point.
Photo credit: Getty Images via Unsplash
