The Vienna Convention on the Law of Treaties (.pdf) defines a treaty as "an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation."
Treaties can be referred to by a number of different names: international conventions, international agreements, covenants, final acts, charters, memorandums of understandings (MOUs), protocols, pacts, accords, and constitutions for international organizations. Usually, these different names have no legal significance in international law.
Treaties may be bilateral (two parties) or multilateral (between several parties) and a treaty is usually only binding on the parties to the agreement. An agreement "enters into force" when the terms for entry into force as specified in the agreement are met. Bilateral treaties usually enter into force when both parties agree to be bound as of a certain date.
For definitions of key terms, see the U.N. Treaty Reference Guide.
A. If you aren't sure if a treaty exists, or you don't have a citation or an exact title, gather information:
Then, start your search with a secondary source:
B. Other strategies include the following:
There are several reliable databases containing treaties from the United Nations Treaty Series (1946-present).
Many international organizations and non-governmental organizations maintain treaty collections by region and by topic. Fortunately, several of the legal research guides listed below, have organized these collections.
Also look for Research Guides on specific international law subjects, such as Environmental. Law, Human Rights Law, and Private International Law for treaty collections by subject.
Note: Many of these guides will suggest beginning your research in the EISIL treaty database. Unfortunately, EISIL is getting a long-overdue revision and is currently not available.
Bilateral treaties where the United States is not one of the parties can be located using the following strategies: