As the Cold War fades, leaders and theorists alike speak of a new era, when democracy and open trade will join hands to banish outright war. With insight and irreverence worthy of The Prince, John Mearsheimer exposes the truth behind this idyllic rhetoric: in a world where no international authority reigns, hegemony is the only insurance of security. Of little consequence are trade, treaties, or the bonds of international organizations; because even an ally's intentions are uncertain, states must be ready to strike first when danger lurks. Having exploded onto the scene with his sensational Atlantic article, Mearsheimer has forged his bracing analysis in the heated policy debates following the fall of the Soviet Union. Here is the culmination of a provocative career--a tour de force that formally advances his theory of" offensive realism" and, as supporting evidence, unveils a comprehensive, eye-opening history of modern states and their hawkish ways. With its authority and unrelenting honesty, this book will invigorate academics, vex politicians, and excite even the casual observer of international affairs.