In this fundamental text, Hedley Bull explores three key questions: What is the nature of order in world politics? How is it maintained within the contemporary states system? And do desirable and feasible alternatives to the states system exist? Contrary to common claims, Bull asserts that the sovereign states system is not in decline. Rather, it persists and thrives, as it is essential to maintaining an international world order. More than three decades after its publication, Bull's classic work continues to define and direct research in international relations. In this thirty-fifth anniversary edition, the text has been updated and includes a new interpretive foreword by the world's leading expert on Bull and his contributions to the theory, structures, and practices of world politics. The Anarchical Society identifies and confronts the unwritten rules supporting the international order across history, despite sweeping changes in laws and institutions. It considers and rejects the idea that the states system is giving way to an alternative world government or some method of neo-medieval rule or that the states system has ceased to be viable or compatible with objectives such as peace, economic justice, and ecological control. Bull also reviews and comments upon a variety of proposals for states system reform.