A treaty is "an international agreement concluded between States in written form and governed by international law,” according to the Vienna Convention of the Law of Treaties. Treaties may also be called accords, conventions, covenants, agreements, charters, statutes, protocols and other terms. To research treaties, it is important to understand terminology used in relation to treaties and treaty actions. (See the lower middle box on this page for some basic definitions.)
The sources of international law are substantially different than the sources of domestic U.S. law. Article 38 of the Statute of the International Court of Justice identifies conventions (or treaties) as one of the sources of international law that the Court applies in resolving disputes. (See the full list of sources in the box below.)
In part, Article 38 of the Statute of the International Court of Justice states:
1. The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply:
a. international conventions, whether general or particular, establishing rules expressly recognized by the contesting states;
b. international custom, as evidence of a general practice accepted as law;
c. the general principles of law recognized by civilized nations;
d. subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.