The book is structured to perform a role both as a primer to those who wish to understand the strategic issues and key concepts in cyberspace, as well as to provide sufficient pointers to those who wish to have an in-depth understanding on specific issues.Among the major issues examined are the efficacy of the concept of cyber deterrence, the troubled history of norm-making in cyberspace, protecting critical infrastructure from crippling cyber attacks, the viability of active cyber defence as a means of responding to the sheer scale of attacks, and its attendant legal and ethical issues. Emerging technologies and their potential impact on an already dynamic domain are also the subject to scrutiny, as also the various models of public-private partnership in cybersecurity around the world.