This book marks the end of my journey from promovenda to philosophiae doctor. Immense gratitude is due to my promotores, Prof. dr. Larissa van den Herik and Prof. dr. Carsten Stahn, for their invaluable guidance and support of my research. I would like to warmly thank the members of the Doctorate Committee, Prof. dr. Niels Blokker, Prof. dr. Andrew Clapham, Prof. dr. Kevin Jon Heller, Prof. dr. Madeleine Hosli and Dr. Ingrid Leijten, for their thoughtful comments on the manuscript, and Dr. Jens Iverson for agreeing to serve on the Opposition Committee. Special thanks are extended to my colleagues at the Grotius Centre for International Legal Studies at Leiden Law School, where I spent five happy years writing and teaching.

Heartfelt thanks to my family for their love and support sent from New Zealand and Australia. I would especially like to acknowledge my mother Chris, who instilled in me a love of learning and teaching. To my husband Matthieu: I am profoundly grateful for your unwavering love, care and understanding. Your resolute belief that I would get there in the end was indispensable. Ehara taku toa i te toa takitahi, ēngari he toa takimano e: my strength is not mine alone, but that of many.

Responsibility for any errors in this work remains my own. The views expressed herein are those of the author and do not necessarily reflect the views of the United Nations.