treaty, in international law, formal agreement between sovereign states or organizations of states. The term treaty is ordinarily confined to important formal agreements, while less formal international accords are called conventions, acts, declarations, or protocols.
A treaty ordinarily deals with the rights and duties of nations, but treaties may also grant specific rights to private individuals. Although treaties deal with a great variety of subjects, they are commonly classified under a few heads. Political treaties deal with (among other things) alliances, war, cessions of territory, and rectification of boundaries. Commercial treaties may govern fisheries, navigation, tariffs, and monetary exchange. Legal treaties concern extradition of criminals, patent and copyright protection, and the like.
Treaties are designed to regularize the intercourse of nations, and, as such, they are the source of most international law. In some countries treaties are a part of the law of the land and are binding upon all persons. In the United States the Supreme Court has held that a treaty automatically abrogates any state or federal statute in conflict with it.
Treaties have existed ever since states came into existence. Records survive of Mesopotamian treaties dating before 3000 BC, and in the Old Testament many treaties are mentioned. The Greeks and the Romans had elaborate ceremonials to emphasize the sanctity of treaties, and many current treaty practices have classical antecedents.
Negotiation, Ratification, and Interpretation
A treaty is negotiated by duly accredited representatives of the executive branch of the government; for the United States negotiations are ordinarily conducted by officials of the Dept. of State under the authority of the President. The preliminaries are not usually open to the public, but the record of all protocol (i.e., the minutes) is preserved for use in case the treaty provisions require subsequent interpretation. Technical experts draft the text, which the government representatives then sign.
The treaty is next ratified by the signatory states in accordance with their regular practice. In the United States the Constitution requires that a treaty must be approved by two thirds of the Senate (executive agreements, however, which are undertaken through the President's powers and do not need the Senate's approval, account for a large number of the international agreements of the United States). It has been argued that such wartime agreements as those made by President Franklin Delano Roosevelt at the Yalta Conference were in effect secret treaties. A treaty comes into effect when the ratifications are formally exchanged.
Members of the United Nations are required to register their treaties with that organization (following the like practice of the League of Nations), and a treaty that has not been registered may not be invoked before a UN agency. If treaties between UN members conflict with their obligations under the Charter of the United Nations, the Charter takes precedence.
The interpretation of treaties, like that of all legal documents, may present great difficulties. There is no tribunal with compulsory and final jurisdiction to interpret a treaty; parties may, however, voluntarily submit a dispute to the International Court of Justice (World Court) or the Permanent Court of Arbitration (Hague Tribunal).
Treaties may come to an end in various ways. Most provide for a date of expiration or a time at which notice to terminate must be given if the treaty is not to continue in effect for another specified period. Treaties terminate if one of the signatory states becomes politically extinct or (in the case of political treaties) if the parties are at war with one another. The outbreak of war need not necessarily bring a treaty to an end, however, and provisions compatible with a state of hostilities remain in force, as long as they are not expressly terminated. Treaties relating to the laws of war, of course, remain in effect during hostilities. A treaty may be terminated by mutual consent, and breach of a treaty by one party entitles the other to abrogate it.
See H. Blix, Treaty-making Power (1960); P. Reuter, Introduction to the Law of Treaties (1989); A. D. McNair, The Law of Treaties (rev. ed. 1986); J. A. Grenville and B. Wasserstein, The Major International Treaties Since 1945 (1988).