Targeted Killings of Nuclear Scientists: Assessing Israel's Attack Legality under International Humanitarian Law

Abstract

International Humanitarian Law (IHL) protects civilians from attack unless they directly participate in hostilities (DPH). In June 2025, Israel launched Operation Rising Lion, a series of targeted strikes against Iranian nuclear scientists, claiming that they were directly participating in Iran’s nuclear weapons programme and thus constituted lawful military objectives. The attack also caused a number of civilian casualties. This study analyzes the exact legal status of the scientists to determine whether their work in the nuclear program makes them lose their civilian protection and become lawful targets. Furthermore, this study examines whether Operation Rising Lion complied with the fundamental principles of IHL, namely the principles of distinction, proportionality, and precautions. This research employs a normative legal research method. The objective of this study is to provide a clear legal analysis of these targeted strikes and assess the overall legality of the military action. Ultimately, this study concludes that although Iranian nuclear scientists may qualify as DPH under the extensive approach, the strikes cannot be considered lawful. The use of powerful munitions in densely populated residential areas indicates that the operations were indiscriminate in nature. By claiming that the resulting civilian casualties were incidental, Israel has misused the concept of proportionality to justify what in substance amounts to violations of the principle of distinction and the prohibition of indiscriminate attacks.