Wright, T. M. & Greig, J. M. (2012) "Staying the Course", Conflict Management and Peace Science, 21 pages. doi: 10.1177/0738894211433162. URL: http://dx.doi.org/10.1177/0738. Abstract▼ The use of peacekeeping to manage conflicts in the international system has grown since the end of the Cold War. While much attention has been devoted to what makes peacekeeping successful, the outcome of peacekeeping is ultimately tied to the willingness of the intervening actor(s) to ?stay the course? and continue the mission until its objectives are complete. In this article we focus upon the empirical puzzle of peacekeeping missions? sustainability. After states and international organizations overcome the collective action problem of forming a mission and deploying it, it is puzzling that so many missions drop out before completion. We adopt a competing risks framework in our analysis to identify the forces that determine whether peacekeepers stay until the end of a conflict or withdraw early. Our explanation argues that peacekeepers are more likely to stay the course as the capacity of the mission increases, the costs and risks of peacekeeping diminish, and traction towards peace is observed.