Turkey’s decision on its role in the Iraq war in 2003 illustrates the power—and limits—of parliaments as actors in foreign policy. Traditionally, assemblies are not seen as important players in the foreign policies of parliamentary democracies. Instead, cabinets are generally considered the chief policymaking authorities. If the government enjoys a parliamentary majority, legislatures typically support the cabinet, if they are brought into the process at all. The March 1, 2003 vote by the Turkish parliament to not allow the United States to use Turkey as a base for the Iraq invasion challenges this conventional wisdom on parliamentary influence (in addition to many interest-based explanations of foreign policy). This paper examines this decision in the context of the role of parliaments in foreign policies and explores the relationships between parliamentary influence, leadership, intraparty politics, and public opinion.