It has never been more important to understand how international law enables and constrains international politics. By drawing together the legal theory of Lon Fuller and the insights of constructivist international relations scholars, this book articulates a pragmatic view of how international obligation is created and maintained. First, legal norms can only arise in the context of social norms based on shared understandings. Second, internal features of law, or 'criteria of legality', are crucial to law's ability to promote adherence, to inspire 'fidelity'. Third, legal norms are built, maintained or destroyed through a continuing practice of legality. Through case studies of the climate change regime, the anti-torture norm, and the prohibition on the use of force, it is shown that these three elements produce a distinctive legal legitimacy and a sense of commitment among those to whom law is addressed.

Winner of the ASIL Creative Scholarship Award 2011

'Jutta Brunné and Stephen Toope have written an engagingly readable and perceptive book that draws fruitfully on some of Lon Fuller’s ideas, as they explore the ways in which international norms and obligations have emerged and evolved during recent decades.'

Matthew H. Kramer Source: Transnational Legal Theory

'… exceedingly good … a highly convincing account of the emergence of international law.'

Wibren van der Burg Source: University of Toronto Law Journal