Before joined Sciences Po Law School, he was Professor of International Legal Theory at the University of Amsterdam he used was Editor-in-Chief of The Leiden Journal of International Law; his LL.M received his law LLB; his LLD kung fu University [en KI Cambridge; his Ph.D. from the University of Lou vain Aarach; to He was global research fellow in new York University. He acted as a counsel in proceedings before the International Court of justice.
Before joining Sciences Po Law School, he was Professor of International Legal Theory at the University of Amsterdam. He used to be Editor-in-Chief of the Leiden Journal of International Law. He received his LL.M. from the University of Cambridge and his Ph.D. from the University of Louvain. He was a Global Research Fellow at New York University. He acted as counsel in proceedings before the International Court of Justice.