Unlike conventional weapons or remotely operated drones, autonomous weapon systems can independently select and engage targets. As a result, they may take actions that look like war crimes—the sinking of a cruise ship, the destruction of a village, the downing of a passenger jet—without any individual acting intentionally or recklessly. Absent such willful action, no one can be held criminally liable under existing international law.
Criminal law aims to prohibit certain actions, and individual criminal liability allows for the evaluation of whether someone is guilty of a moral wrong. Given that a successful ban on autonomous weapon systems is unlikely (and possibly even detrimental), what is needed is a complementary legal regime that holds states accountable for the injurious wrongs that are the side effects of employing these uniquely effective but inherently unpredictable and dangerous weapons. Just as the Industrial Revolution fostered the development of modern tort law, autonomous weapon systems highlight the need for “war torts”: serious violations of international humanitarian law that give rise to state responsibility.