Objectives: On March 1, 2003, the Turkish parliament rejected a government motion that would involve Turkey in the Iraq war and allow U.S. forces to use Turkish territory in an offensive against Iraq. This decision has been considered as a significant departure from traditional Western-oriented Turkish foreign policy. We investigate the reasons behind this rather unexpected foreign policy decision. Method: To systematically examine the decision-making process and the outcome, we utilize the "decision-units framework." We present primary and secondary evidence from government and media sources and utilize interviews conducted with some of the high-level decisionmakers that were involved in decision making at the time. This article combines traditional methodological tools, such as elite interviews and process tracing, with novel approaches in foreign policy analysis studies. Results: The nature of the decision-unit, decision-making rules, the extraordinary circumstances surrounding the AKP (Adalet and Kalkinma Partisi-Justice and Development Party) leadership, and the absence of a strong and decisive leader shaped the outcome. Conclusion: The Turkish parliament's decision on its role in the Iraq war is an interesting and informative case for foreign policy studies. It challenges the conventional wisdom on parliamentary influence in foreign policy making in parliamentary regimes. Under certain circumstances-even when a single-party enjoys parliamentary majority-parliaments can be major players in foreign policy decision making.