I could not have produced this book without the assistance and support of others. It began life as a doctoral thesis completed at the University of Oxford under the supervision of Dapo Akande and Professor Guy Goodwin-Gill. Dapo’s sharp intellect, close attention to detail and extensive knowledge of international law undoubtedly pushed me to produce a better thesis and book. He regularly went beyond the call of duty by providing feedback from the other side of the world, whether by email between Yale and The Hague or by skype between Oxford and Australia, and his flexibility and tireless availability enabled me to pursue a range of endeavours while still maintaining a strong level of supervision throughoutmydoctorate. I amalsoextremely grateful tomy supervisor during the final term of my doctorate, Professor Guy Goodwin-Gill, who invested a considerable amount of time and energy to comprehend the entire project at a late stage. His feedback on the final drafts ofmy thesis and his general advice on the road to publication were invaluable. Dr Sarah Percy and DrRoger O’Keefe examinedmy masters thesis at the University of Oxford, and their exacting standards helped me to improve my work and develop it into a doctoral proposal. My doctoral thesis examiners, Professors Vaughan Lowe and Nigel White, also provided helpful comments, and I am grateful for their assistance. The Rhodes Scholarship funded my studies at Oxford for three full years. I will forever be indebted to the Rhodes Trust for the financial support, self-confidence and phenomenal professional and personal opportunities that the Scholarship provided. I was also fortunate to receive a Wingate Scholarship during the final stages of my doctorate. Parts of Chapters 3, 4 and 5 of this book develop work that appeared in ‘Common Article 1: AMinimumYardstick for Regulating PrivateMilitary and Security Companies’ (2009) 22 Leiden Journal of International Law 779–99. I gratefully acknowledge the journal’s permission to reprint the relevant passages.