Providing a much-needed study on cybersecurity regime building, this comprehensive book is a detailed analysis of cybersecurity norm-making processes and country positions, through the lens of multi-stakeholder diplomacy. Multi-disciplinary and multi-national scholars and practitioners use insights drawn from high-level discussion groups to provide a rigorous analysis of how major cyber powers view multi-stakeholder diplomacy. Looking at how past cybersecurity initiatives and multi-stakeholder negotiations in other fields illuminate its dynamics, this book will help put states' approaches towards multi-stakeholder cyber diplomacy into perspective, and frame the role of private actors in cybersecurity regime building. Evaluating the most promising institutional arrangements and mechanisms for implementing cybersecurity, this book combines top-down analyses relevant to the design of international cybersecurity regimes with bottom-up case studies, tracing the approaches of important states towards multi-stakeholder participation in cyber diplomacy. With a wealth of policy-relevant findings, this book will be welcomed by practitioners and scholars of international law, international organisation and international cybersecurity as well as multi-stakeholder governance and multilateral regimes. Policymakers and diplomats involved in international cybersecurity processes will also benefit from its cutting-edge comparative analysis of the approaches of key cyber powers.