This book examines hybrid threats within the broader context of a security crisis in Europe. As geopolitical tensions increase and great power rivalries intensify, can states protect their communities? While conventional wars are fought, parallel battles take place by more subtle and non-violent means. This multi-disciplinary book examines how hybrid threats undermine political governance and social stability in liberal democracies, covering aggressors, targeted states and victimized communities. It seeks to address how aggressor states undermine liberal democracies under the threshold of conflict, and the role played by hybrid threats as aggressor states prepare for full-scale war. The chapters also explore how liberal democracies organize and interact to detect hybrid threats, arguing that, in order to increase resilience, politicians and government agencies must involve the private sector and citizens in threat-reduction policies. The analysis builds upon the latest research in the international crisis management literature. This book will be of interest to students of security studies, hybrid warfare, defence studies and International Relations, as well as professional practitioners. The Open Access version of this book, available at http://www.taylorfrancis.com, has been made available under a Creative Commons Attribution (CC-BY) 4.0 license. Odd Jarl Borch is a Professor of Strategy at the Nord University Business School, Bodo, Norway. He is the author of more than 150 scientific publications. He has served on several government committees within industry development, safety and preparedness, including the Norwegian Total Preparedness Commission. Tormod Heier is a Professor of Military Strategy and Operations at the Norwegian Defence University College, Norway. He has edited or authored 14 books, on crisis management, security and defence policy, and military conflicts. He was awarded The Norwegian PEN’s Ossietzky Price for Freedom of Speech in 2017, and The Norwegian Army’s Medal of Merit in 2023.