In 1993 the first Clinton administration declared environmental security a national security issue, but by the end of the Bush administrations environmental security had vanished from the government's agenda. This book uses changing US environmental security policy to propose a revised securitisation theory, one that both allows insights into the intentions of key actors and enables moral evaluations in the environmental sector of security. Security and the Environment brings together the subject of environmental security and the Copenhagen School's securitisation theory. Drawing on original interviews with former key players in United States environmental security, Rita Floyd makes a significant and original contribution to environmental security studies and security studies more generally. This book will be of interest to international relations scholars and political practitioners concerned with security, as well as students of international environmental politics and US policy-making.