| The idea of collective security has developed as a scheme for the maintenance of international order. The collective security system of the United Nations is a manifestation of combination of intellectual and institutional developments in the realm of collective security. This study focuses on a systematic understanding of collective security in theory and practice.;In the first part, a theoretical framework of collective security is developed in the context of Grotian tradition, which posits the use of force by international society of states. Two sets of criteria are used: a collective security system and its performance is examined respectively in terms of the requirements of collective security, i.e., consensus, commitment, and organization; The factors and conditions which influenced the two UN collective actions are explained in the aspects of institutions of international society: international system, diplomacy, war, and international organization.;The UN took collective security actions twice in its entire history: the Korean War of 1950-1953 and the Persian Gulf War of 1990-1991. Using the theoretical framework above, the second part analyzes and assess the performance of the UN and the reasons why and how the UN collective security worked in the two wars as it did. The UN actions in both wars are examined, compared, and contrasted to each other and against "ideal type" of collective security. The two wars have similarities and differences in terms of these elements.;Empirical findings in this study suggest that the UN collective security was conducted in a modified form and is likely to be so in the future. The contemporary trends regarding UN actions in international peace and security indicate an increasing use of the UN collective mechanism. |
