Book excerpt: This book explores the challenges leaders in intelligence communities face in an increasingly complex security environment and how to develop future leaders to deal with these issues. As the security and policy-making environment becomes increasingly complicated for decision-makers, the focus on intelligence agencies ‘to deliver’ more value will increase. This book is the first extensive exploration of contemporary leadership in the context of intelligence agencies, principally in the ‘Five Eyes’ nations (i.e. Australia, United States, United Kingdom, Canada, and New Zealand). It provides a grounded theoretical approach to building practitioner and researcher understanding of what individual and organisational factors result in better leadership. Using interviews from former senior intelligence leaders and a survey of 208 current and former intelligence leaders, the work explores the key challenges that leaders will likely face in the twenty-first century and how to address these. It also explores what principles are most likely to be important in developing future leaders of intelligence agencies in the future. This book will be of much interest to students of intelligence studies, strategic studies, leadership studies, security studies, and international relations.