Volume 28 of the Yearbook of International Humanitarian Law addresses a topic crucial for the application of international humanitarian law (IHL): facts. Despite their fundamental importance, facts are fiercely contentious within IHL. During armed conflict, the factual determinations needed to assess conduct are particularly difficult to make – parties often conceal or manipulate information, and ‘fake news’ and disinformation are regularly used to discredit alleged violations of IHL. Indeterminacies within IHL itself also give rise to significant factual problems – for instance, how much knowledge is needed to determine that a certain object is indeed a military objective, and what obligations (if any) do parties have to disclose information used for deciding to target it?

Considering the particularly debated role of facts within contemporary IHL, this Volume contains 11 chapters dedicated to the rigorous doctrinal, empirical, and theoretical analysis of the topic. Issues addressed include the gendered features of facts in IHL, the role of different types of fact-finding bodies in armed conflict, and facts relating to specific aspects of IHL, including the protection of nuclear facilities, outer space hostilities, and the use of artificial intelligence. In addition, several chapters centre on the fundamental role of facts in ensuring respect for IHL, as well as accountability for potential violations. The Volume concludes with the Year in Review, which describes and analyses the most important IHL-related developments that took place during 2025.

The Yearbook of International Humanitarian Law is a leading annual publication devoted to the study of IHL. It has always strived to be at the forefront of the debate of pressing doctrinal and theoretical questions of IHL, and provides an international forum for high-quality, peer-reviewed research on this crucial branch of international law. Distinguished by contemporary relevance, the Yearbook of International Humanitarian Law bridges the gap between theory and practice, serving as a useful reference tool for scholars, practitioners, military personnel, civil servants, diplomats, human rights workers, and students.

Heike Krieger (Editor-in-Chief), Free University of Berlin, Department of Law/Public Law, Berlin, Germany, heike.krieger@fu-berlin.de. Pablo Kalmanovitz (Editor), Inst Tecnológico Autónomo de México, Department of International Studies, Mexico City, Mexico, pablo.kalmanovitz@itam.mx The first part of this editor’s affiliation should read: Instituto Tecnológico Autónomo de México (ITAM). Eliav Lieblich (Editor), Tel Aviv University, Buchmann Faculty of Law, Tel Aviv, Israel, elieblich@tauex.tau.ac.il. James Patrick Sexton (Managing Editor), T.M.C. Asser Instituut, Research Department, The Hague, The Netherlands, j.sexton@asser.nl.