The Criminal Responsibility of Private Military and Security Company Personnel under International Humanitarian Law

International humanitarian law (IHL) encompasses rules that bind states, armed groups, and individuals for the purpose of solving humanitarian problems arising from armed conflicts. These rules protect persons affected by armed conflicts and limit the amount of violence in methods and means of warfare. 1 Within this frame, specific substantive and procedural norms establish when and how violations of IHL give rise to individual criminal responsibility, and thus contribute to its implementation. 2 Since private military and security companies (PMSCs) are not 'classical' actors in war contexts, the subjection of their personnel to IHL and their liability for war crimes constitute a complex issue. PMSCs play an increasingly important global role, specifically by providing support, advice, and security services in hostile environments. Their employees often work alongside state troops in the field through maintenance and operational activities. The complexity of the situation in which private contractors act is perfectly illustrated by the logistic support provided by Blackwater employees in a battle of US Marines protecting the headquarters of the Coalition Provisional Authority (CPA) in Najaf against the Iraqi Militia, where they had to ferry in ammunition supplies and conduct a marine to safety.