International institutions are once again at the center of the substantive and intellectual agendas of international politics. Practitioners are asking tough questions about reformulating existing institutions such as NATO or the United Nations and its agencies; old institutions like the GATT are being transformed into new ones like the WTO; and completely new institutions like NAFTA, APEC, and LRTAP are being created. At the same time, the relevance and importance of international institutions have returned to the center of intellectual debate for the first time in a generation. Realists are renewing their claims that institutions are irrelevant or else derivative of more fundamental issues of power politics; liberals are renewing claims about the central role of institutions in the governance of existing and prospective international issues.

This debate over the importance of international institutions has multiple causes, practical and intellectual. The end of the cold war reopened a set of institutional issues that had been frozen in the bipolar division of international politics and created possibilities for reorganizing our international security and economic affairs. In addition, changes in technology and interdependence have resulted in new issues such as the global environment and increased the significance of long-standing issues such as trade. While these substantive concerns have made the intellectual debate more important, its origin lies equally in the social science-wide return to institutional analysis. Some three decades after an earlier descriptive institutionalism was overthrown by a move toward behavioralism, the social sciences are recapturing an analysis of institutions that had been significantly neglected in the meantime.