International lawyers typically start with the legal. What is a legal as opposed to a political question? How should international law adapt to the unforeseen? These are the routes by which international lawyers typically reason. This book begins, instead, with the non-legal. In a series of case studies, Fleur Johns examines what international lawyers cast outside or against law - as extra-legal, illegal, pre-legal or otherwise non-legal - and how this comes to shape political possibility. Non-legality is not merely the remainder of regulatory action. It is a key structuring device of contemporary global order. Constructions of non-legality are pivotal to debate in areas ranging from torture to foreign investment and from climate change to natural disaster relief. Understandings of non-legality inform what international lawyers today do and what they refrain from doing. Tracing and potentially reimagining the non-legal in international legal work is, accordingly, both vital and pressing.