Accounting for the complexity of the law applicable to modern armed conflicts

© Oxford University Press 2019. It is almost trivial to observe that the law applying to modern armed conflicts is full of complexities. Such complexities are, after all, the bread and butter of legal academics, who have produced mountains of books and articles on the various relevant topics, but the extent of these complexities can be overstated. While legal academics debate the finer points of the interaction between international humanitarian law (IHL) and international human rights law (IHRL), in the majority of today’s armed conflicts the law is reasonably practical and clear. It might not be complied with, but that is not because of its supposed complexity or lack of clarity. If, for example, the parties to armed conflicts with the highest cost in human lives and property (e.g., in Syria or Yemen) observed only the bare fundamentals of the principle of distinction, the world would be spared much suffering. Noncompliance has little to do with the law’s complexity. But complexity is nonetheless a major feature of a subset of modern armed conflicts, especially those involving foreign intervention by Western powers. The purpose of this chapter is to clarify our understanding of how complexity works, where it comes from, and how it is managed. To do so, this chapter first develops two themes: the multiple causes of complexity and the decentralized system for managing this complexity. These themes are then explored in more detail in the context of the law on the use of force, or jus ad bellum, IHL, and IHRL.