An in-depth examination of the evolving peace and security activities of the United Nations Secretary-General in the context of developments in international politics. The constraints and opportunities which the Office has experienced under Pérez de Cuéllar and Boutros-Ghali in the transition to the post-Cold War world and the controversy which has surrounded the Office reflects the volatility and uncertainty of the UN in a changing environment. It is argued that the Secretary-General's activities in the 1990s reflect a development of the international civil service beyond the classical model.