From the Peace of Westphalia to the present, the ruling elites of kingdoms and states have attempted one international bargain after another for a variety of purposes. Whether it is to protect the integrity of a ruling system such as aristocratic orders, the prevention of power politics, or the mere hope of avoiding the scourge of world war, the West has consistently sought to use multilateral institutions to accomplish these ends, among others. What causes these multilateral attempts to succeed or fail, and more importantly, what is multilateralism's center of gravity? This book suggests that the fear and attractions of state leaders-and the circumstance within which they perceive these fears and attractions-is the center of gravity of the West's most important multilateral attempts. These attempts include the Peace of Westphalia, the British Act of Union, the Congress System, the League of Nations, the United Nations, and the North Atlantic Treaty Organization (NATO). Furthermore, it is these human traits among elite figures in the context of historical book that best explain the success or failure of Western Multilateralism over that of the application of theoretical sciences.