This article argues that mediation and political engagement by third parties can contribute to peacebuilding by strengthening the political processes in countries exiting civil conflict. Third-party engagement can create the political space within which long-term reconstruction, development, and reconciliation issues can be discussed among national actors. Given that peace agreements are frequently mere cease-fires representing short-term deals among elites, mediation and political engagement can assist the transformation of these deals into long-term commitments and inclusive national politics. Specifically, mediation can contribute to peacebuilding in three ways. First, mediators contribute to peacebuilding by working toward peace agreements that serve as frameworks for the opening up of the political process as opposed to agreements that lock in detailed, long-term governance models and concentrate power in the hands of the wartime elites. Second, in the period immediately following the signing of peace agreements, mediation helps parties adhere to the agreements and settle any remaining issues. Third, mediation contributes to making transitional governments workable and, as much as possible, ensures that they gradually lead to more inclusive political processes.