Autonomous weapon systems and IHL compliance: A constrained legal optimisation problem

Arguments have been made both for and against military use of autonomous weapon systems (AWSs) on the basis of how they will help or hinder a state in meeting its international humanitarian law (IHL) obligations. Often, these arguments are made in isolation, or they fail to address all of the potential compliance concerns related to autonomous weapons. This is not ideal. It means the bearers of legal obligations must locate, assess and piece together the disparate arguments into a coherent structure if they are to know whether they can legitimately utilise a particular autonomous capability and, if so, in what circumstances. This article offers a high-level description of a conceptual framework which can be used to organise and assess legal arguments about autonomous weapons. It proposes that the task of integrating autonomous capabilities into an armed force may be viewed as a constrained optimisation problem wherein the task is to find the optimal balance between the fundamental principles of IHL while also satisfying all normative, technological and strategic/operational constraints.