The 1986 accident at the Chernobyl plant highlighted the need to examine and clarify the obligations imposed by international law on States engaged in nuclear and other ultra-hazardous activites. This volume brings together in full the texts of the most important materials necessary for a comprehensive examination of the international law and communication issues arising from nuclear and other accidents with transboundary effects. The texts reproduced include multilateral and bilateral treaties, non-binding acts of international organizations and private associations of scholars, and national legislation. Their chronological presentation reflects the development of the law up to and including the 1986 IAEA Conventions on Early Notification and Assistance and the 1987 Resolution of the Institut de Droit International on Transboundary Air Pollution. Each text is introduced by a Note summarizing its background and main provisions, and is accompanied by a select bibliography. The signatories and parties to the treaties are set out in full. This work is a publication of The Annenberg Washington Program in Communications Policy Studies of Northwestern University and the Research Centre for International Law, University of Cambridge.