This incisive book provides an extensive analysis of the robust array of international law applicable across the spectrum of international conflict and security. With a particular focus on new and emerging technologies and domains such as cyber and outer space, Laurie Blank illustrates how international conflict and security law applies to 21st century challenges. From conflict prevention to the use of force, the law of armed conflict to transitional justice, this book offers an in-depth examination of how these legal frameworks address the most fundamental questions for security at the human, national and international levels: how to prevent and reduce escalation of conflict; how to protect States, their territory and their core national interests; how to protect individuals and their rights; how to maintain and restore international peace; how to resolve conflicts; and how to promote justice and reconciliation after conflict. Overall, the book creates a multifaceted and insightful picture of how the international legal system functions as a comprehensive - if still sometimes fractured - framework. International Conflict and Security Law will be essential reading for both graduate and undergraduate students studying security policy, international law, conflict resolution and armed conflict. It will also provide a well-rounded exploration of the field as a whole for policy makers, practitioners and academics.