Drawing from a range of materials, Martti 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. Originally published in English in Finland in 1989, this reissue includes a newly written Epilogue by the author.