"The underlying reasons why rivalry among states will remain the moving force of international relations are set out in Paul Hirst's War and Power in the 21st Century, a short book written before 11 September that is worth more than a truckload of the ephemera that have appeared in the aftermath of the attack." The New Statesman "This short, well-written contribution to Polity's 'Themes for the 21st Century' series contains a bold set of reflections on the future of states and war." Political Studies Review "A very useful study." Australian Journal of Political Science