A Treaty refers to an official agreement negotiated between two states (or countries) that is signed by officials from each state (country).

Additional Sources

A formal agreement between two or more states, as in reference to terms of peace or trade.

Duhaime Legal Dictionary

A formal agreement between two states signed by official representatives of each state.

Encyclopedia Britannica

A binding formal agreement, contract, or other written instrument that establishes obligations between two or more subjects of international law (primarily states and international organizations). The rules concerning treaties between states are contained in the Vienna Convention on the Law of Treaties (1969), and those between states and international organizations appear in the Vienna Convention on the Law of Treaties Between States and International Organizations or Between International Organizations (1986).


A contract in writing between two or more political authorities (as states or sovereigns) formally signed by representatives duly authorized and usu. ratified by the lawmaking authority of the state. Dictionary

n. a pact between nations which, if entered into by the United States through its Executive Branch, must be approved by "two-thirds of the Senators present," under Article II, section 2 of the Constitution, to become effective. Presidents sometimes get around the Senate by entering into "Executive Agreements" with leaders of other countries which are a mode of cooperation and not enforceable treaties.

Lect Law Library

A treaty is a compact made between two or more independent nations with a view to the public welfare treaties are for a perpetuity, or for a considerable time. Those matters which are accomplished by a single act, and are at once perfected in their execution, are called agreements, conventions and pactions.

On the part of the United States, treaties are made by the president, by and with the consent of the senate, provided two-thirds of the senators present concur.

No state shall enter into any treaty, alliance or confederation, nor shall any state, without the consent of congress, enter into any agreement or compact with another state, or with a foreign power. Const. Art. I

A treaty is declared to be the supreme law of the land, and is therefore obligatory on courts whenever it operates of itself without the aid of a legislative provision; but when the terms of the stipulation import a contract, and either of the parties engages to perform a particular act, the treaty addresses itself to the polit-ical, not the judicial department, and the legislature must execute the contract before it can become a rule of the court.

Treaties are divided into personal and real. The personal relate exclusively to the persons of the contracting parties, such as family alliances, and treaties guarantying the throne to a particular sovereign and his family. As they relate to the persons they expire of course on the death of the sov-ereign or the extinction of his family. Real treaties relate solely to the subject-matters of the convention, independently of the persons of the contracting parties, and continue to bind the state, although there may be changes in its constitution, or in the persons of its rulers.

The Free (Legal) Dictionary

A treaty is an agreement in written form between nation-states (or international agencies, such as the United Nations, that have been given treaty-making capacity by the states that created them) that is intended to establish a relationship governed by International Law. It may be contained in a single instrument or in two or more related instruments such as an exchange of diplomatic notes. Various terms have been used for such an agreement, including treaty, convention, protocol, declaration, charter, Covenant, pact, act, statute, exchange of notes, agreement, modus vivendi ("manner of living" or practical compromise), and understanding. The particular designation does not affect the agreement's legal character.

Though a treaty may take many forms, an international agreement customarily includes four or five basic elements. The first is the preamble, which gives the names of the parties, a statement of the general aims of the treaty, and a statement naming the plenipotentiaries (the persons invested with the power to negotiate) who negotiated the agreement and verifying that they have the power to make the treaty. The substance of the treaty is contained in articles that describe what the parties have agreed upon; these articles are followed by an article providing for ratification and the time and place for the exchange of ratifications. At the end of the document is a clause that states "in witness whereof the respective plenipotentiaries have affixed their names and seals" and a place for signatures and dates. Sometimes additional articles are appended to the treaty and signed by the plenipotentiaries along with a declaration stating that the articles have the same force as those contained in the body of the agreement.


A treaty is an agreement under international law entered into by actors in international law, namely sovereign states and international organizations. A treaty may also be known as: (international) agreement, protocol, covenant, convention, exchange of letters, etc. Regardless of the terminology, all of these international agreements under international law are equally treaties and the rules are the same. (Note that in United States constitutional law, the term "treaty" has a special meaning which is more restricted than its meaning in international law; see below.)

Treaties can be loosely compared to contracts: both are means of willing parties assuming obligations among themselves, and a party to either that fails to live up to their obligations can be held liable under international law. The central principle of treaty law is expressed in the maxim pacta sunt servanda—"pacts must be respected".

The Vienna Convention on the Law of Treaties has codified the customary international law on treaties, entering into force in 1980. States that have not ratified it yet may still recognize it as binding in as much as it is a restatement of customary law.