'The importance of both micro- and macro-level networks to the organisation and operation of the business of national security has only recently begun to be widely appreciated. This book provides an outstanding analysis of the dynamics and effectiveness of security networks that will fascinate scholars and practitioners alike. An original contribution that will provoke further research.' Grant Wardlaw, Australian National University, Australia 'Security networks are notoriously hard to study. This book provides one of the first comprehensive empirical accounts of their structure, culture and effectiveness in a national security context. By systematically examining the multiple dimensions that influence their operations, it considerably enhances the conceptual toolbox needed to understand these complex organisational arrangements.' Benoit Dupont, Université de Montréal, Canada