In this article, I aim to reorient debates, in International Relations and Law, about the relationship between law and war. In the last decade, writers have challenged common understandings of law as a limit on, or moderator of, warfare. They have instead claimed that law is often used as a ‘weapon of warfare’, describing such uses as ‘lawfare’. Below, rather than arguing that law is either a constraint on or an enabler of warfare, I examine how law comes to be represented as such. Specifically, I examine representations, primarily by US military and other governmental lawyers, of ‘non-Western’ invocations of the laws of war, which seek to constrain the policies or practices of the US or Israeli governments. I show how these authors cast such invocations as not law at all, but as tools of war. I suggest that this move rests on, and reproduces, colonial discourses of ‘non-Western’ legal inadequacy or excess, which serve to render ‘non-Western’ law ‘violent’ or ‘war-like’. I show that the referents and boundaries of law and war are stabilised by notions of civilisational difference, which serve to give meaning to what law is, what war is, and whether particular claims or practices are understood as martial or legal.