Who Acts When Autonomous Weapons Strike? The Act Requirement for Individual Criminal Responsibility and State Responsibility.

This article analyzes the legal responsibility for war crimes arising from the use of autonomous weapon systems (AWS) enabled by strong artificial intelligence—referred to as "intelligent AWS"—particularly focusing on the material act (actus reus) required for prohibited attacks under international humanitarian law. It argues that the material act of such war crimes is invariably carried out by the human user who directs or launches the attack, even when unintended engagements result from system failures, and that these acts are attributable to the state employing the weapon under established international law principles. The article critiques views suggesting a responsibility gap due to the autonomous nature of intelligent AWS, emphasizing that state responsibility does not depend on a causal link between human conduct and the breach but on the normative attribution of acts by state organs, including armed forces. It concludes that despite technological advances, intelligent AWS remain tools under human and state control for which existing international humanitarian law and state responsibility frameworks apply, cautioning against allowing the opacity of AI systems to undermine accountability in armed conflict.