Nearly all scholarship on radical political movements suggests that participation in formal politics will lead to moderation. Yet Iraq's Sadrist Movement, the Shi'a Islamist group headed by Muqtada al-Sadr, defies the widespread assumption that political inclusion leads to moderation by giving a group a greater stake in the system. This paper will examine the Sadrist Movement to explore the impact of unstable security conditions on the calculations and actions of political movements. In late 2004, the Sadrist Movement recognized the legitimacy of the Iraqi state, ceased using violence and entered electoral politics. The literature suggests that the Sadrist Movement should have continued to moderate in response to further political and material incentives. However, in 2006 the Sadrists returned to violence and grew increasingly hostile toward democratic politics. Why did the Sadrist Movement reverse course in this manner? This work argues that unstable environments, such as that of post-2003 Iraq, can cause parties to reject the incentives of inclusion within the state political system.