Hybrid threats represent one of the rising challenges to the safe and effective management of digital systems worldwide. The deliberate misuse or disruption of digital technologies has wide-ranging implications for fields as diverse as medicine, social media, and homeland security. Despite growing concern about cyber threats within many government agencies and international organizations, few strategies for the effective avoidance and management of threats or the prevention of the disruption they can cause have so far emerged. This book presents multiple perspectives based upon a NATO Science for Peace and Security Programme Advanced Research Workshop on 'Resilience and Hybrid Threats' held in Pärnu, Estonia from 26-29 August 2018, and includes a mixture of workshop summary papers and invited perspectives from world experts. Topics include the development of strategies for the protection and recovery of systems affected by hybrid threats, and the benefits of those strategies under different disruption scenarios. The role of risk and resilience assessment pertaining to the information domain is a common focus across all perspectives. Offering an overview of resilience-based decision making through an approach that integrates the threats and dependencies related to infrastructural, informational, and social considerations, the book will be of interest to all those whose work involves the security of digital systems.