When does a decision-maker's shift on a major policy issue represent a genuine reassessment in his or her beliefs as opposed to tactical maneuvering? This article provides a framework to improve our confidence that a policy shift represents “complex learning,” which entails the adoption of new goals, rather than “simple learning,” which refers to a change in means but not goals. Challenging the conventional wisdom on learning, it argues that decision makers who alter their foreign policies incrementally are more likely to have had a fundamental rethinking of their underlying assumptions on a core issue than those who exhibit sudden shifts in their foreign policy decisions absent a traumatic event. The public declarations of Israel's three most recent premiers—Ariel Sharon, Ehud Olmert, and Benjamin Netanyahu—in support of the establishment of a Palestinian state are used to illustrate the utility of this framework. Whereas Sharon and Olmert underwent complex learning, Netanyahu's swift change appears to represent merely a tactical response to pressure from the United States.