Are the workings of the international world to be explained scientifically, or are they to be understood through their inward meaning? In Explaining and Understanding International Relations philosopher Martin Hollis and international relations scholar Steve Smith join forces to analyse the dominant theories of international relations and to examine the philosophical issues underlying them. The book has three parts. In the first the authors review the growth of the discipline since 1918, pose the 'level of analysis' problem of whether to account for a sytem in terms of its units or vice versa, and contrast the demand of scientific method with those of interpretative understanding. In the second they apply the contrast to four factors often cited in accounting for international behaviour - the international system, the state, bureaucracies, and decision-making individuals. Rival accounts of the games nations play are offered in readiness for the final part, where the authors propose a theoretical agenda, air their differences, and invite readers to take sides. By tackling deep theoretical issues with lucidity and verve this book will excite debate among theorists and students of international relations while also engaging thought about the philosophical character of the social sciences.