In contrast to most previous research on foreign-policy change, this article investigates how an individual decision-maker can have an impact on major changes in foreign policy. The article takes as its theoretical point of departure the concept of leader-driven change, which focuses on the determined efforts of a political leader to change policy. Empirically, the article investigates the change that occurred in Denmark’s foreign policy when its government decided to participate in the United Nations sanctions against Iraq in August 1990. The article finds that the foreign minister was the main initiator of the policy change, that his personal characteristics played a decisive role, and that the Gulf crisis created a window of opportunity for the foreign minister to initiate the change in policy. In implementing the policy change, however, the foreign minister could not act independently, since he needed the support of other political actors. On the basis of these empirical findings, the article suggests a new theory of foreign-policy change.