The attitude of the United States toward international organization, however, has been very ambivalent. Presumably the United States has gone along with, and has sometimes displayed enthusiasm for, the organizing process for essentially the same reasons that have moved other states: it has recognized the practical necessity, in its own interest, of developing and participating in systematic arrangements for dealing with the complex problems of the modern world. It has also shared the ideal of creating a global mechanism better adapted to promoting and maintaining peace and human welfare. Even when it has been skeptical of the utility or importance of particular multilateral institutions, the United States, like most other states, has generally inclined to the view that it can ill afford to be unrepresented in their functioning or to give the appearance of being indifferent to the ideals they purport to serve.
America's limited and informal engagement in the operation of the League of Nations illustrated the first of these points. The United States could bring itself neither to join nor to abstain entirely from the League. Its enthusiastic adherence to the United Nations in 1945 can be interpreted as in part a symbolic act of repentance and reversal, a conscious repudiation of the American abandonment of the League. Moreover, already during World War II, American statesman had been very active in planning for the postwar world. Even though idealistic and quite unrealistic plans predominated—such as Franklin Roosevelt's strong advocacy of a "one world" system including something approaching a world government, the abolition of the balance-of-power concept and of geographical spheres of influence, and Secretary of State Cordell Hull's enthusiasm for uninhibited global free trade—this still compared favorably to the passivity of Britain, the nation that had hitherto dominated the international system. While the British hesitated to embark on any postwar planning exercises for fear of undermining the war effort, Washington began planning for the postwar world before the country had even become a belligerent power. After Pearl Harbor, and once Hitler had declared war on the United States, it was unlikely that a return to the political isolationism of the interwar years would occur despite the continuation of a strong isolationist strand in American thinking.
Thus, America's joining the United Nations with New York as the new organization's headquarters and San Francisco as the venue for the ceremonial signing of the UN Charter was much more than a mere symbolic denial of indifference to the high ideals enunciated in the charter. It was, more positively, a declaration of resolve to accept a position of leadership in world affairs, an affirmation of the intention to play a role that this country had never before assumed in international relations. In this sense American ratification of the UN Charter was a unique act, a dramatization of an event of peculiar significance: the decision of the United States to transform its approach to world affairs. The country's subsequent role in the distribution of Marshall Plan aid to western Europe and, above all, its adherence to the North Atlantic Treaty Organization in April 1949, reaffirmed the same point and even strengthened it. After all, NATO membership carried more concrete obligations and more definite alliance commitments than did membership in the United Nations. Article 5 of the NATO treaty pledged all member states to regard an attack on a member state as an attack on itself. Although during the ratification process the U.S. Senate insisted that the last decision of how the United States would react to any such emergency had to be left to Congress, article 5 imposed a firm obligation of some form of assistance on NATO member states.
In most cases decisions by the United States to take part in international agencies can be assumed to be motivated in much the same way and can be assigned essentially the same meaning as such decisions by other states. Neither in the case of the United States nor in other instances does it make sense to regard acceptance or support of international organizations as in itself a demonstration of virtue comparable with the virtue sometimes attributed to the individual because he goes to church and pays his tithe. International agencies are not embodiments of a sacred cause but, rather, instruments of the purposes of their members, susceptible of use to promote both noble and ignoble causes. States join them for mixed reasons, and the mere act of affiliation typically provides no solid information about the constructiveness, willingness to cooperate, or the peacefulness of the intentions of the state concerned.
America's inhibitions and reservations concerning international organization are a blend of the typical and the peculiar. Despite the vogue of creating new international organizations since the 1990s and the strong trend toward economic and financial globalization, it is clear that all states maintain some measure of reluctance to become too encompassed, circumscribed, and absorbed by international bodies. It is perhaps unfair to accuse them of harboring the illogical desire to have their cake and eat it too, for in the relations between organization and sovereignty, just as in the relations between national society and individualism, the real question is not which to choose but how much of each to include in the package. In either the domestic or the international case, however, the perennial tension between control and autonomy remains, and it becomes especially acute when circumstances require reconsideration of the necessary and proper balance between them. The fact that states need and want international organizations does not eliminate their desire to retain as much as possible of the autonomy that the traditionally decentralized international system affords them. The tension between the desire for effective and useful international organization and the urge to continue to enjoy and exploit the freewheeling possibilities of a simpler era profoundly affects the behavior of states in creating, joining, and operating multilateral agencies. In the Western world both NATO and in particular the European Union are prime examples of this.