Welcome to Guest Blogger Jan Klabbers

We here at Opinio Juris are thrilled to welcome Jan Klabbers as our latest guest blogger.  Professor Klabbers is professor of international organizations law at the University of Helsinki, and Director of the Academy of Finland Centre of Excellence in Global Governance Research. This semester he’s also a Fellow in residence at NYU’s newly established Straus Institute for the Advanced Study of Law & Justice.  Professor Klabbers is one of the world’s leading experts in the law of treaties.  Check out his impressive and provocative The Concept of Treaty in International Law if you’ve never done so, or take a gander at his more recent work such as Treaty Conflict and the European Union.  As the EU-focus suggests, Professor Klabbers also specializes in international institutional law, having authored a series of books and articles on the subject, including Introduction to International Institutional Law.  Most recently, Professor Klabbers has ventured into the growing debate about constitutional theory and international law with a recently edited volume (where he was joined by Anne Peters and Geir Ulfstein), The Constitutionalization of International Law.