This editorial article starts with a a generic reflection on interagency and in­ternational cooperation and coordination. Then, the two editors report on their personal experience. First, Dr. Fluri critically assesses the experience and lessons learned from the coordination of national, internationally supported initiatives to reform security sectors and enhance their effectiveness, effi­ciency, and oversight. Then Prof. Prezelj focuses on interorganizaitonal coop­eration and coordination in counter-terrorism, crisis management and critical infrastructure protection. Finally, the article briefly presents the volume and each individual contribution.