Abstract: This book presents a critical view of international law as an argumentative practice that aims to 'depoliticise' international relations. Drawing from a range of materials, Koskenniemi demonstrates how international law becomes vulnerable to the contrasting criticisms of being either an irrelevant moralist Utopia or a manipulable façade for State interests. He examines the conflicts inherent in international law - sources, sovereignty, 'custom' and 'world order' - and shows how legal discourse about such subjects can be described in terms of a small number of argumentative rules. This book was originally published in English in Finland in 1989 and though it quickly became a classic, it has been out of print for some years. In 2006, Cambridge was proud to reissue this seminal text, together with a freshly written Epilogue in which the author both responds to critiques of the original work, and reflects on the effect and significance of his 'deconstructive' approach today.