Prof. dr. Niels Blokker was appointed as Professor of International Institutional Law to the 'Schermers Chair' in 2003. He graduated from Leiden University (1984), where he also defended his dissertation (1989). In 2000 he was appointed senior legal counsel at the Netherlands Ministry of Foreign Affairs. His publications include Proliferation of International Organisations (co-authored with Henry G. Schermers, 2000) and The Security Council and the Use of Force (samen met Nico Schrijver, 2005). His research concentrates on the law of international organisations, with emphasis on the law of the United Nations. As a member of the Netherlands delegation to the PrepCom for the International Criminal Court, he participated in the negotiations on the crime of aggression. At the Clio Conference of 2012 prof. dr. Niels Blokker will discuss the authorizations of the UN Security Council of the use of violence. For example restitution 678 concerning Iraq and restitution 1973 concerning Libya.