Targeted Killing of Nuclear Scientists Under International Humanitarian Law: Israel’s Operation Rising Lion 2025 Against Iranian Scientists

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 article examines the legality of these strikes under IHL. It first analyses whether Iranian nuclear scientists can be classified as DPH making them lawful military objectives. It then evaluates whether Israel’s Operation Rising Lion complied with the core principles of IHL, namely distinction, proportionality, and precautions in attack. This article concludes that although Iranian nuclear scientists may qualify as DPH under the extensive approach, the strikes cannot be considered lawful. Israel has asserted that its operations fully complied with IHL and that any civilian casualties were incidental and proportionate to the military advantage anticipated. However, 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.