While extensive research has been conducted on the conditions and processes that make a negotiated settlement most likely to sustain peace, less work has been done on the peace implementation stage and its impact in facilitating the transition from war to quality peace, the author argues. Though the terms of a negotiated settlement are fundamental for quality peace, these generally vague and sometimes contradictory terms must be prioritized, redefined, and made operational during the phase of peace implementation. This chapter focuses on how prioritizing the demilitarization of politics early in the process provides a favorable environment for implementing a negotiated settlement and institutional reforms. In many cases, demilitarizing politics during the peace implementation phase is more important than the actual provisions contained in the peace agreement. A critical element in explaining why some peace implementation processes lead to quality peace while others collapse is intra-party and inter-party dynamics that change the perceived feasibility of political strategies. The chapter is divided into three sections. The first outlines a framework for understanding peace implementation as a process of transforming the institutions and patterns of governance developed during a civil war into organizations, rules, and norms that can support quality peace. The second section suggests that there are two ways to implement peace agreements—execute blueprints or transform institutions. Finally, the third section argues that demilitarization of politics (by prioritizing building interim institutions and transforming former rebel groups into political parties) can generate incentives that raise the perceived costs of military strategies and increase the perceived benefits of engaging in political processes.