This book analyzes intelligence relations in an unsecure world and provides contributions on intelligence processes, interstate intelligence relations and hybrid warfare. Tactical, operational and strategic intelligence relations, both within and between intelligence agencies, and between states, are essential to support decision makers. This book ties together how intelligence adapts to security changes, global power shifts and the trend from globalization to a more nationalistic approach. During such changes, there is a need to analyze intelligence sharing relationships. Bringing together practitioners and academics, the book presents a plurality of approaches relative to intelligence relations that seek to advance the debate in the field.