Standard conceptions of the relationship between international law and war in International Relations (IR) mostly oscillate between the sceptical view that law is mostly irrelevant in times of conflict, and the optimistic view that law is a meaningful moral standard that effectively constrains violence. Modern asymmetric conflicts between liberal democratic states and non-state actors such as the Taliban,al-Qaeda, orHamaschallenge these conceptions, however, as they are at once increasingly legal and extremely violent. Drawing inspiration from IR and International Law (IL) scholarship from multiple theoretical paradigms, this article examines the legal asymmetries before, during, and after asymmetric conflict. Noting that law is at once a useful tool and a strong normative force, it argues that a good understanding of legal asymmetries can supplement existing theories of asymmetric war, continue the dissolution of false dichotomies and open up interesting avenues of research in IR, and help both scholars and policymakers understand how international law influences modern asymmetric conflict against non-state actors.