Much of the world will be living in broadly liberal societies for the foreseeable future. Sustainability and security, however defined, must therefore be considered in the context of such societies, yet there is very little significant literature that does so. Indeed, much ecologically-oriented literature is overtly anti-liberal, as have been some recent responses to security concerns. This book explores the implications for sustainability and security of a range of intellectual perspectives on liberalism, such as those offered by John Rawls, Robert Nozick, Frederick Hayek, Ronald Dworkin, Michael Oakeshott, Amartya Sen and Jurgen Habermas.