Private military and security companies (PMSCs) have been used in every peace operation since 1990, and reliance on them is increasing at a time when peace operations themselves are becoming ever more complex. This book provides an essential foundation for the emerging debate on the use of PMSCs in this context. It clarifies key issues such as whether their use complies with the principles of peacekeeping, outlines the implications of the status of private contractors as non-combatants under international humanitarian law, and identifies potential problems in holding states and international organizations responsible for their unlawful acts. Written as a clarion call for greater transparency, this book aims to inform the discussion to ensure that international lawyers and policy makers ask the right questions and take the necessary steps so that states and international organizations respect the law when endeavouring to keep peace in an increasingly privatized world.

A growing number of states use private military and security companies (PMSCs) for a variety of tasks, which were traditionally fulfilled by soldiers. This book provides a comprehensive analysis of the law that applies to PMSCs active in situations of armed conflict, focusing on international humanitarian law. It examines the limits in international law on how states may use private actors, taking the debate beyond the question of whether PMSCs are mercenaries. The authors delve into issues such as how PMSCs are bound by humanitarian law, whether their staff are civilians or combatants, and how the use of force in self-defence relates to direct participation in hostilities, a key issue for an industry that operates by exploiting the right to use force in self-defence. Throughout, the authors identify how existing legal obligations, including under state and individual criminal responsibility should play a role in the regulation of the industry.