Professor of public international law at the University of Groningen in the Netherlands since 2005;
Chair of the Department of International Law at the Faculty of Law, Groningen;
Chair of the Department of Social Sciences at the University College Groningen (liberal arts college);
Academic Director of the LL.M. Programmes in Public International Law and International Human Rights Law and of the LL.B. Programme in International and European Law of the University of Groningen.
(Co-)director of the Law Faculty’s research programme "Energy and Sustainability";
Director of Studies of the International Law Association (ILA);
Editor of the Netherlands International Law Review.
From 2001-2013 member and chair of the Advisory Committee on Questions of Public International Law (CAVV), advising the Dutch government and parliament.
He has taught Public International Law at bachelor, master and PhD level since the early 1990’s at Leiden University, Oxford University and Groningen University. As guest lecturer he taught courses at various universities in the world, including in Ghana, Turkey and Brazil.
Academic interests and specialization include: the development of public international law in general; sustainable development law; international dispute settlement; international investment law; international diplomatic law; law of international peace and security; law of the sea.