This book provides in-depth coverage and analysis of the international law, rules and principles that govern the use of force. Through a unique intra-disciplinary perspective, it examines how the law on the use of force functions within the international legal system and how it interacts with other relevant areas of the law. This includes arms control law, the law governing the use of the international commons, the law of armed conflict and human rights law, and the law of international responsibility. It offers an accessible guide to the law on the use of force to students and practitioners, alongside providing a unique perspective on the place and function of the law on the use of force within the wider legal landscape which will appeal to both academic professionals and others interested in how law regulates the use of force.