I am a Canadian lawyer and Associate Professor of International Law at Tilburg Law School. My interest in laws that promote peace extends to the following fields of research: transitional justice, comparative constitutional law, international criminal law, international human rights, public international law and the law of international peace and security. As the recipient of a Swiss National Science Foundation research fellowship, I am currently completing my Habilitation on post-conflict constitutions and peace (forthcoming, Cambridge University Press). I am also the author of Interpreting Crimes in the Rome Statute of the International Criminal Court, published by Cambridge University Press in 2014. Prior to this, I combined my academic work with more than a decade of legal practice, including at the International Criminal Court, International Criminal Tribunal for the former Yugoslavia, UN Human Rights Committee, UN High Commissioner for Refugees, the Federal Court of Canada, an international commercial law firm and various organisations doing pro bono legal work. As legal adviser to the chief negotiators on the crime of aggression from 2007 to 2010, I assisted with drafting the definition of this crime for the Rome Statute. 


My work has appeared inter alia in the American Journal of International Law and the European Journal of International Law as well as been cited by judges of the International Criminal Court and the UN International Law Commission. In addition to my most recent book with Cambridge University Press, I have contributed to the editing of several other Cambridge publications (UN Human Rights Treaty Bodies: Law and Legitimacy (2012), The Travaux Préparatoires of the Crime of Aggression (2012) and The Crime of Aggression: A Commentary (2016)). I studied international relations and political science (University of Western Ontario) as well as law (University of Toronto) before obtaining my doctorate in law under the supervision of Prof. Claus Kress at the University of Cologne, where I also taught.

Down to the wire - final efforts to draft compromise language for the Resolution on the Crime of Aggression at the Kampala Review Conference, adopted in the early hours of 12 June 2010.



Transitional Justice

I am currently writing a book on post-conflict constitutions and their contribution to peace. In the past, I have examined the work and design of truth and reconciliation commissions, land reform policies, the legality of amnesties, the nature of peace agreements, the peace versus justic debate, post-conflict responses to child soldiers, as well as some disarmament, demobilization and reintegration case studies.


Aurelio Cal, et al. v. Attorney General of Belize, Supreme Court of Belize (for the Claimants); landmark decision on the legality of government leases of ancestral Mayan lands.

Comparative Constitutional Law

I am currently tracing the historical evolution of more than 200 constitutional arrangements during periods of conflict in order to understand inter alia their use as peacemaking instruments. I am also carrying out both small- and large-N comparative functional studies of more than two dozen post-conflict constitutions negotiated since 1990. Among other things, I have been asked to advise on elements of Iraq's 2004 interim constitution and offer expert commentary on defining the concept of interim constitutions.

International Criminal Law

I have researched and written extensively on the work of the International Criminal Court as well as several ad hoc international criminal tribunals and have a special interest in rule of law issues. In my book, Interpreting Crimes in the Rome Statute of the International Criminal Court (CUP, 2014), I develop a method of interpretation - containing interpretive principles, arguments and aids - for more than ninety crimes defined in the Rome Statute. This method reconciles rules of interpretation in the Rome Statute with those contained in the Vienna Convention on the Law of Treaties.

International Human Rights

My research to date has focused on internationally recognized human rights, their regional impact, the relationship between this field and neighbouring fields of international law, fair trial rights, especially the principle of legality, the rights of the child, indigenous rights, international refugee law and the work of the UN Human Rights Committee as well as other UN treaty bodies.


Charkaoui v. Canada (Citizenship and Immigration), Supreme Court of Canada (for the Federation of Law Societies); trilogy of cases on the constitutionality of national security laws applicable to suspected terrorists and enacted in the aftermath of 9/11. 


Prosecutor v. Joseph Kony, et al., International Criminal Court (for the Prosecutor); application for the first set of arrest warrants to be issued by the Court; the accused have allegedly committed multiple counts of crimes against humanity and war crimes.

Public International Law

My research interests include the sources, nature, interpretation, codification and progressive development of international law as well as the work of various United Nations bodies. I have been invited to meet with current and former members of the International Law Commission (ILC), as well as members of the British Foreign Office to comment on and critique the ILC's work. I have also been asked to offer expert advice on the issue of State responsibility for providing military aid to security forces who then use this to commit gross human rights violations, as well as the doctrine of collective punishment under international law.


Prosecutor v. Mladen Naletilic and Vinko Martinovic, International Criminal Tribunal for the former Yugoslavia (Trial Chamber); judgment finding the accused guilty of multiple counts of crimes against humanity and war crimes as well as aquitting them on several counts.

Law of International Peace and Security

In addition to teaching this subject and practicing in this field, I have written on the crime of aggression, the use of force, terrorism, national security laws, executive war powers as well as international legal constraints in peace negotiations.