Military and police forces play a crucial role in the long-term success of political, economic and cultural rebuilding efforts in post-conflict societies. Yet, while charged with the long-term task of providing a security environment conducive to rebuilding war-torn societies, internal security structures tend to lack civilian and democratic control, internal cohesion and effectiveness and public credibility. They must be placed under democratic control and restructured and retrained to become an asset, not a liability, in the long-term peacebuilding process. External actors from other nations, regional organizations and the United Nations can be of assistance in this process, by creating a basic security environment, preventing remnants of armed groups from spoiling the fragile peacebuilding process and by facilitating reform of the local security sector. This book offers analyses of an international group of academics and practicioners with direct experiences with security sector reform programmes in different parts of the world.