The UN Charter, signed in 1945, created two distinct things: a set of basic rules of conduct for governments and a formal organization with its own powers. Both the organization and the rules are legally binding and are therefore a kind of constraint on the sovereignty of member states, and they also make possible new kinds of international politics that can be very useful to states. They are therefore empowering as well as constraining. The formal organization of the United Nations is composed of separate organs including the Security Council, the General Assembly, and the Secretariat. Each has a specific area of competence and they vary in how much authority they exercise over member states. The basic rules include commitments to refrain from the use of force to solve international disputes, to respect the decisions of the International Court of Justice, and to pay the required dues to the United Nations itself. The two aspects of the UN Charter amount to something like a constitution for the international system.
The United Nations Charter defines the UN as a formal institution of limited powers as well as a generalized system of constitutional principles to govern all of inter-state politics. The institutional parts of the UN, such as the General Assembly and the Security Council, are required to operate within these principles, but the principles themselves are refined and brought to life through the daily practices and actions of the states and others who make use of them. The principles and the practices need to be understood together, as neither is really dominant. When, for instance, the Charter says that the Security Council has “primary responsibility for the maintenance of international peace and security” (Art. 24(1)), the only way to know what is meant by the key terms “primary” and “international peace and security” is to look at how the Council and others have used these terms through the years in debates, justifications, and argument. This chapter therefore looks at the UN with one eye on the legal language of the Charter and the other eye on the artful applications of that language in the practical diplomacy and manipulations of states.