Steve A. Yetiv has developed an interdisciplinary, integrated approach to studying foreign policy decisions, which he applies here to understand better how and why the United States went to war in the Persian Gulf in 1991 and 2003. Yetiv’s innovative method employs the rational actor, cognitive, domestic politics, groupthink, and bureaucratic politics models to explain the foreign policy behavior of governments. Drawing on the widest set of primary sources to date - including a trove of recently declassified documents - and on interviews with key actors, he applies these models to illuminate the decision-making process in the two Gulf Wars and to develop theoretical notions about foreign policy. What Yetiv discovers, in addition to empirical evidence about the Persian Gulf and Iraq wars, is that no one approach provides the best explanation, but when all five are used, a fuller and more complete understanding emerges. Thoroughly updated with a new preface and a chapter on the 2003 Iraq War, Explaining Foreign Policy , already widely used in courses, will continue to be of interest to students and scholars of foreign policy, international relations, and related fields.