• Legis Scriptor

Basics of Treaty Law

Authored by - Sania Vinayan

Keywords - Treaty Law, United Nations, Basics, Public international law, law of treaties, consent to be bound


This article aims to give a brief overview of the basics of Treaty Law. It deals with the definition of treaties, its enforcement and the United Nation’s role in the area of Treaty law under the ambit of Public International law.


Treaty Law is a subject matter of treaties in the area of international law. Treaties are essentially agreements between sovereign States and sometimes include international organizations as well. Moreover, it may also include laws concerning international treaties. In legal terms “ ‘treaty’ means 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.”[1] They are similar to contracts that are bound by International law. Treaties are the key foundation of the Public International Law. A treaty can be bilateral (between two States) or multilateral (between three or more States). Lastly, they can also include the creation of rights for individuals.[2]

Does Treaty Law and Law of Treaties mean the same?

No, Treaty Law and Law of Treaties are not mean the same. There is a slight difference between the two.

Firstly, Treaty Law deals with the subject matter of treaties, i.e. how treaties address specific issues such as the Law of the Sea or extradition measures. Whereas the Law of Treaties deals with how treaties come into being, which includes the process of drafting, administering, and regulating treaties.[3]

Can all agreements between two or more states be called a treaty?

It is important to keep in mind that not all agreements between two or more countries are called treaties. All parties to the contract should agree that it is bound by international law. Only then the treaty can come into force. The UN plays a major role in the formation and deposition of these treaties.

Role of the United Nations (UN)

A UN agreement codifies the rules that guide international conventions. It is called the Vienna Convention on the Law of Treaties. This document provides a legal framework that requires to be followed to form treaties. It lays down the rules on the commencement and conclusion of treaties as well as the interpretation, application, modification, amendment, and terms of invalidity, etc. This is a step by the UN in pursuit of peace and coordination between States. A treaty comes into force only once it is ratified by all the concerned parties/ States. The UN Secretary-General is the depository of these treaties.

What must it take for a State to be part of a Treaty?

To become a party to a treaty, a State must express, through a concrete act, its willingness to undertake the legal rights and obligations contained in the treaty – it must “consent to be bound” by the treaty.[4]

How does a State “consent to be bound” to a treaty?

A State can express its consent to be bound by a treaty in several ways, as specifically set out in the final clauses of the relevant treaty. The most common ways are the definitive signature, ratification, acceptance, approval, and accession.[5] By consenting, the State agrees to become a party and indicates its willingness to accept the legal rights and obligations included in the treaty once it comes into force.

Some multilateral treaties have a time limit to their signature. Multilateral treaties often provide that they will be “open for signature” only until a specified date, after which signature will no longer be possible. Once a treaty is closed for signature, a State generally may become a party to it through accession. Some multilateral treaties are open for signature indefinitely. Most multilateral treaties on human rights issues fall into this category.[6]

How are Treaties enforced?

There is no supreme body or organization that penalizes or coerces the States if they breach provisions of any treaty. This is because all States are the sovereign authority. Hence, there can be no other sovereign body above them all. That is not to say that these treaties are ineffective.

There is, established by the UN, an International Court of Justice (ICJ). All matters of grievances relating to international disputes and breach of treaty provisions can be taken to the said court i.e. ICJ. Although, before a case can go before the Court, a State ought to have accepted the jurisdiction of the Court, either in general or in relation to a specific case. A State that has not accepted the Court’s jurisdiction cannot be forced to appear before the International Court of Justice.[7]

Different treaties may also create different treaty body regimes to encourage the parties to abide by their obligations and undertake actions required for compliance. For instance, the Human Rights Committee monitors the implementation of the International Covenant on Civil and Political Rights; the Committee on the Elimination of Racial Discrimination monitors implementation of the International Convention on the Elimination of All Forms of Racial Discrimination; and the Committee against Torture monitors implementation of the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment.[8]

There are other international dispute resolution systems such as the International Tribunal for the Law of the Sea, Permanent Court of Arbitration, and other settlement bodies of the World Trade Organisation (WTO).

Other measures can be used such as sanctions and use of force etc. by the Security Council to protect international peace and security in case of any violations of peace or acts of aggression.


Treaties can be claimed as one significantly effective tool in making sure that there is unambiguity over subjects that are of immense importance and can help in contributing to international peace, security, and coordination. As an increasing number of countries move towards a more global approach, the importance of international laws such as treaties also rises.

[1] Article 2(1)(a) of Vienna Convention on the Law of Treaties Done at Vienna on 23 May 1969

[2] Guide to Public International Law: Treaties by University of Melbourne -

[3] What is Treaty Law?

[4] Fact sheet of UN-

[5] Supra note 4

[6] Supra note 4

[7] Supra note 4

[8] Supra note 4