On 7 September 1988 the Secretary General of the United Nations, Mr. Javier Perez de Cuellar, received the degree of Doctor Honoris Causa from the University of Leiden. This degree was granted as a tribute to his contribution to international peace, justice and international law. Following an introduction by Professor H.G. Schermers (Leiden University), Professor P.H. Kooijmans (Leiden University) delivered the laudatio in honour of Mr. Perez de Cuellar. Mr. Kooijmans praised the efforts of the Secretary General in seeking settlement of international disputes, and he stated that Mr. Perez de Cuellar had at crucial moments used his personal prestige in order to achieve a breakthrough in the peaceful settlement of international disputes. In particular Mr. Kooijmans referred to the Iran\Iraq, Namibia, Afghanistan, and Western Sahara disputes. In particular Mr. Kooijmans referred to the Iran/Iraq, Namibia, Afghanistan, and Western Sahara disputes. The United Nations is now regaining its relevance as an international peacekeeping force after the various crises of the 1970s and 1980s. Professor Kooijmans contended that the leadership of the Secretary General has to a great extent been the source of this rejuvenation.