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.
When conducting research on treaties, it is important to have a working knowledge of basic terminology, including:
Accession: process by which a state that was not among a treaty's original signatories becomes a party to it
Consent to be bound: A formal act by a state (such as a definitive signature, ratification, acceptance, approval or accession) by which the state agrees to submit to a treaty's provisions.
Convention: usually, a multilateral treaty that sets forth rules of international law applicable within its subject matter
Depositary: For modern conventions, the entity that manages and notifies parties of the signatures, ratifications, accessions, as well as amendments and reservations. Examples: the Secretary-General of the United Nations. a regional organization (such as the Organization of American States), an international organization (such as the International Committee of the Red Cross) or a nation state.
Entry info force: For conventions, the date that the treaty entered into binding force for the states that had become parties at that time; this date is different for states the become parties subsequently
Objection: a statement by a party rejecting a reservation made by another party, which may render the reservation ineffective between it and the reserving state or may constitute an intention that the treaty not enter into force between the the reserving and objecting parties
Party (or state party): a country that has ratified the treaty or consented to be bound by the provisions of the treaty
Protocol: usually, a treaty or international agreement that supplements a previous treaty or international agreement
Ratification: the international act whereby a state indicates its consent to be bound to a treaty if the parties intended to show their consent by such an act.
Reservation: usually made at the ratification stage, a statement for a party to a multilateral convention that rejects a provision thereof, thus modifying the treaty's impact on that party to the extent of the reservation
Signatory: a country that has signed a treaty, expressing its intention to join the treaty; this may not be the same as the formal step of ratification or accession to the treaty
Understanding: a statement by a party to a convention that expresses an interpretation of a treaty provision, which may limit the applicability of such provision to that country