After World War II, a new range of multilateral international institutions developed, leading to increased interaction between nations and a consequent need for new types of representatives beyond those in traditional embassies. The emergence of the United Nations, a series of specialized agencies associated with it, and other international organizations—ranging from regional security groups to free trade areas to military alliances— resulted in an extensive series of regularly scheduled meetings at which the United States needed to be represented. The increasing multilateralism of world affairs and the increasing importance of global issues necessitated dealing with groups of nations rather than addressing issues bilaterally with individual governments, which is the function of embassies.
Reflecting the fact that the UN system required a different level of representation than do individual nations, the U.S. representative to the UN was usually given cabinet rank to make possible his or her participation in policymaking. Hence, although the UN representative received instructions from the Department of State, she or he also ranked well above other ambassadors. While representatives from all nations at the UN held the rank of ambassador, their responsibilities were far more extensive than those of traditional ambassadors, since they dealt with envoys from all other governments in the world. In recognition of this fact, each nation's head of mission at the United Nations was called a permanent representative.
Individuals with the rank of ambassador, often drawn from the regular Foreign Service ranks, were assigned to represent the United States at a number of other permanent regional multilateral organizations. These included intergovernmental organizations such as the European Union and the North Atlantic Treaty Organization. Other individuals with ambassadorial rank were sent to observe the meetings of regional organizations.
An increasing number and range of issues were addressed as global questions during the last quarter of the twentieth century. This required U.S. representation at many organizations, conferences, and meetings dealing with topics on a worldwide, multilateral basis. These sessions cover a wide range of vital subjects. Specialized agencies, commissions, and programs of the United Nations dealt with human rights, the environment, trade, drug trafficking, crime, corruption, food, agriculture, health, air and maritime trade, postal and telegraph linkages between nations, intellectual property rights and protections, refugees, population, and many additional issues. All were problems that spanned national boundaries, and hence required international cooperation, which necessitated negotiations and agreements by national governments. In addition, the UN convened a series of world conferences to deal with topical issues, particularly the various aspects of development. The annual meetings of organizations formed by treaties to enforce or monitor the enforcement of treaty provisions often dealt with vital issues of international peace and security, such as arms proliferation; weapons of mass destruction including nuclear, chemical and biological weapons; and the rights of civilians in wartime.
These meetings and conferences required representatives with particular expertise regarding the particular issues under discussion. The representatives involved came from a range of governmental agencies, in addition to the diplomatic corps. Such meetings were often covered by special representatives. Even when the delegation was headed by the Foreign Service officer, the members of the delegation included specialists and even members of Congress. These representatives were appointed on a short-term basis by the president, without confirmation by the Senate.