In this, his most systematic and fundamental work, Hedley Bull explores three key questions: what is the nature of order in world politics?; how is it maintained in the contemporary state system?; and what alternative paths to world order are feasible and desirable? He argues that the system of sovereign states is not in decline and is not an obstacle to world order but its essential foundation. This third edition, marking the 25th anniversary of original publication, includes a substantial new foreword by Andrew Hurrell examining the continuing relevance of The Anarchical Society to subsequent developments in theory and in the structures and practices of world politics.