In 1989, peaceful change, which a leading realist theorist had declared a very low-probability event in international politics less than a decade before, accommodated the most fundamental geopolitical shift of the postwar era and perhaps of the entire twentieth century: the collapse of the Soviet East European empire and the attendant end of the cold war. Many factors were responsible for that shift. But there seems little doubt that multilateral norms and institutions have helped stabilize their international consequences. Indeed, such norms and institutions appear to be playing a significant role in the management of a broad array of regional and global changes in the world system today.

Why has the concept of multilateralism not played a more prominent role in theories of international relations? The prima facie case for the importance of multilateral activity in the international realm would seem great. The world, we constantly tell ourselves, is increasingly drawn together. The Swedish economist Assar Lindbeck argues that most external effects of production and consumption are external not only to the household but also to the country in which they occur. According to many different indicators, interdependence is on the increase in nearly all parts of the world. International political economists talk about global indivisibilities, ranging from peace to pollution. Most important international problems-including pollution, energy, managing airline traffic, and maintaining rules for trade and investment-intrinsically involve many countries simultaneously. What makes a problem international is that often it cannot be dealt with effectively within the national arena. Costs and benefits spill into the external arena. These external effects are frequently so great that domestic goals cannot be accomplished without coordinated multilateral action.

At the end of the 1940s, the United States and several West European states allied to defend themselves against invasion by the Soviet Union. Balance-ofpower theory predicts the recurrent formation of such balances among states. But it says little about the precise nature of the balance, the principles on which it will be constructed, or its institutional manifestations. The North Atlantic Treaty Organization (NATO) has been a peculiar mix. As a formal institution, NATO has through most of its history been distinctly nonmultilateral, with the United States commanding most decision-making power and responsibility. At the same time, NATO provided security to its member states in a way that strongly reflected multilateral principles. Within NATO, security was indivisible. It was based on a general organizing principle, the principle that the external boundaries of alliance territory were completely inviolable and that an attack on any border was an attack on all. Diffuse reciprocity was the norm. In the terms set out by John Ruggie, NATO has generally scored low as a multilateral organization but high as an institution of multilateralism.

Multilateralism, international governance of the “many,” was defined by the United States after 1945 in terms of certain principles, particularly opposition to bilateral and discriminatory arrangements that were believed to enhance the leverage of the powerful over the weak and to increase international conflict. Postwar multilateralism also expressed an impulse to universality (John Ruggie's “generalized organizing principles”) that implied relatively low barriers to participation in these arrangements. A ticket of admission was always required, whether acceding to the General Agreement on Tariffs and Trade (GATT) or joining the International Monetary Fund (IMF) and the World Bank. Nevertheless, the price of that ticket was not set so high that less powerful or less wealthy states could not hope to participate.

Serious consideration of the role of humanitarian norms and institutions in policymaking does not require the abandonment of an interest-based, rational actor model of policy analysis. However, it does require that scholars focus their attention on international institutional arrangements which are normally overlooked by realists but which may determine the ways in which policymakers match their interests with policy options. The analysis presented here assumes that policies are based on policymakers' calculations of national interests, but it posits that these calculations are affected by incentives and policy options emanating from international norm-promoting institutions. The study attempts to explain how the intervention of an institution of this type led policymakers in two cases to reassess and reinterpret their interests on issues of humanitarian norm compliance.

Over the course of the previous two decades, political scientists have become increasingly interested in the relationship between international politics and global trade. Much of the literature on this topic centers on the effects of a hegemonic distribution of power on commerce. Hegemonic stability theorists argue that hegemony is a necessary condition for the existence of a liberal economic order and that in the absence of a hegemon, a liberal international economy is particularly difficult to establish and maintain. However, a growing number of theoretical and empirical critiques have been leveled against the gemonic stability theory, and the issue of whether hegemony helps shape patterns of global trade continues to be the topic of heated debate.