The phantom pain: an international law perspective on the weaponization of infrasound, ultrasound, and microwaves

Abstract There has been much speculation and controversy about the development and effects of weapons based on infrasound, ultrasound, and microwaves over the past decades. However, recent incidents like the Havana syndrome or the alleged clash at the Sino-Indian border revealed that their existence may not be pure fantasy. Reports also indicate that several nations are striving to develop the so-called ‘directed-energy weapons’ by 2030. However, specific legal studies on the topic are rare, even though weapon review is required at an early stage. Thanks to an analysis of scientific studies and clinical trials, this article reveals that infrasound, ultrasound, and microwaves may have serious consequences, and that certain technical issues which affect their weaponization may well be overcome. It then explains how such weapons may comply (or not) with international law. It finds that their use may qualify as prohibited use of force, and even an armed attack. It also demonstrates that diseases, mutilations, and paralysis caused by infrasound, ultrasound, and microwaves may amount to superfluous injury or unnecessary suffering, and explores under what circumstances multidirectional waves comply with the principle of distinction. It then explains in what situations those weapons do comply (or not) with international human rights law, and especially Articles 2 and 3 of the European Convention on Human Rights.