Many states view Private Military and Security Companies (PMSCs) as crucial to implement their security policy. However, reoccurring incidents of human rights violations have led the international community, private sector and civil society to acknowledge the need for more control over the use of PMSCs. Growing state support for The Montreux Document and an ever growing number of signatory companies to the International Code of Conduct for Security Providers (ICoC) show that self-regulation through non-binding norms has shifted to the centre of this debate. This book examines the promises and dangers of emerging non-binding PMSC regulation alongside more traditional forms of law-making such as plans for an international convention on the use of PMSCs. It offers in-depth analysis of legal and political developments that led to the proliferation of The Montreux Document and the ICoC. Identifying the state side of duties and corporate responsibility as leaving gaps and grey zones in international law, it analyses how both instruments address the responsibility to protect and the responsibility to respect. Covering the Private Security Providers' Association's Articles of Association, the most recent developments on the establishment of a PMSC oversight mechanism are included. Finally, the book provides an original theory of how both instruments could become more effective to protect victims against PMSC human rights violations; The Montreux Document by developing into a form of customary international law, the standards of the ICoC framework by developing into more binding normative standards as a form of 'corporate custom'. About the author Corinna Seiberth gained her first degree in law at the University of Basel. She has since worked as a human rights researcher, lecturer and PhD research fellow at the University of Lucerne and the University of Nottingham. She is currently working as a project manager for Usthi Foundation Switzerland working on a development project for tribal children and communities in Orissa, India.