This powerful new book is the first ever examination of the hard edge of how political risk - something faced by every political actor innumerable times per day - is calculated and used in decision making. It opens with an outline of the historical and linguistic origins of risk, a section on the various disciplinary understandings of risk, the 'risk society' concept and how risk has come to be so prominent in the context of environmental disaster and terrorism. The book then defines political risk and looks at its manifestations in the public sector from project to high level political risk. It also looks at risk identification versus risk management and the various processes at work.The final chapters compare the experiences and lessons learned from the case studies and practitioner insights in previous chapters, to formulate a better understanding of what political risk is and what its calculation means in political practice. Finally the author shows how political risk calculation provides a fresh perspective on policy analysis and identifies how political risk is relevant to a broader understanding of politics and political science as well as policy formulation and implementation on the ground.It examines how political actors calculate risk and make decisions with unique findings from over 100 interviews with risk practitioners and politicians. The case studies include post-9/11 US government risk calculation on terrorism, UK government action during the mad cow crisis and Australian experiences of risk calculation in government development plans. It is written by a leading risk theorist, university lecturer and strategic consultant for organizations ranging from Mitsubishi to the Australian military.