Abstract: Despite widespread public opposition to the Iraq War, numerous democracies joined the US-led multinational force. However, while some stayed until the end of coalition operations, and several increased their deployments over time, others left unilaterally. How to explain this variation? While some studies suggest that democratic defection from security commitments is primarily motivated by electoral incentives or leadership change, scholars have not reached a consensus on this issue. To account for the complex interplay between causal factors, this article develops an integrative theoretical framework, using fuzzy-set Qualitative Comparative Analysis (QCA) on original data on the Iraq War involvement of 51 leaders from 29 democracies. The findings document the existence of multiple paths towards coalition defection. Among others, the results show that: (1) leadership change led to early withdrawal only when combined with leftist partisanship and the absence of upcoming elections; (2) casualties and coalition commitment played a larger role than previously assumed; and (3) coalition defection often occurred under the same leaders who had made the initial decision to deploy to Iraq, and who did not face elections when they made their withdrawal announcements.