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 second edition includes a new foreword by Stanley Hoffmann assessing the importance and relevance of Hedley Bull's text some two decades after its initial publication.