2.1 INTRODUCTION TO TREATY LAW
Treaty is a common term including all instruments binding under international law,
concluded between two or more international juridical entities. These juridical entities may
be either States or International Organizations. Generally, treaties signify that the parties
intend to create rights and obligations enforceable under International law. A treaty may also
be known as an agreement, protocol, covenant, convention, pact etc.
The Vienna Convention, 1969, under Article 2(1) (a) 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, concluded between two or more States or other subjects of
international law and governed by international law”. A bilateral treaty is a treaty between
two parties and a multilateral treaty is a treaty between more than two parties.
It is important to note the difference between Law of Treaties and Treaty Law. The former
signifies the subject matter of the treaties i.e. what treaties are trying to regulate, whereas the
latter deals with how treaties come into being and regulation of process of making and
regulating treaties i.e. about how international agreements are made.
Article 38(1) (a) of the ICJ Statute makes a reference to treaties and reads: ‘international
conventions, whether general or particular, establishing rules expressly recognised by the
contracting states’. Treaties include conventions, International agreements, covenants, pacts,
The obligatory nature of treaties is founded upon the customary international law principle
‘pacta sunt servanda’ which means that agreements are binding. Treaties are express
agreements and are a form of substitute legislation undertaken by states.
2.1.2 TYPES OF TREATIES
There are generally two types of treaties: Law-making treaties and Treaty Contracts.
Law-making treaties lay down rules of universal or general application. It is governed by
United Nations Charter or Geneva Convention on the Law of the Sea, 1958. Treaty
Contracts are treaty between two or few states. These types of treaties usually deal with a
special matter concerning these States exclusively.
2.1.3 RELATION OF TREATIES WITH CUSTOMS
When norms of a treaty origin crystallise into new principles of customary law, the
customary norms retain a separate identity even where the two norms may be identical in
Premise of VCLT, 1969
The significance of the concept of treaties in international law was recognized formally by
the VCLT, 1969. The premise of VCLT, 1969 was law creation, creation of rights and duties
between parties and pacta sunt servanda.
2.1.4 THE VIENNA CONVENTION ON THE LAW OF TREATIES, 1969
This convention is referred to as a “treaty on treaties”. It refers only to written treaties. Every
State has the capacity to conclude treaties. It acknowledges the fundamental role of treaties in
the history of international relations.
The VCLT, 1969 does not deal with:
a) Treaties between states & organizations or between two or more organizations;
b) state succession to treaties; or
c) The effect of armed conflict on treaties
The functions/categories of Treaties are given as:
a) Treaties involving bargains between States: They are like contracts, generally
involving few States.
b) Treaties laying down a set of rules: They are law-creating treaties, for eg. Hague
Conventions on the Law of War.
c) Treaties creating an Institution: Akin to a charter of incorporation, for eg. The United
2.1.5 BASIS OF BINDING FORCE OF TREATIES
• Pacta Sunt Servanda: A treaty in force is binding upon the parties and must be
performed by them in good faith. Legally, treaties are enduring instruments; they
cannot be easily disposed of. Internal law may not be invoked to justify a failure to
perform a treaty.
2.1.6 THE MAKING OF TREATIES: STEPS AND FORMALITIES
There are no set overriding requirements of form in treaty formation. Following has to be
generally met before successful treaty formation.
• Who may enter into treaties?
Head of States and Governments, Foreign Ministers, Heads of Diplomatic missions for
adopting the text of the treaty, or any other representative accredited to international
Treaty drafted and agreed by authorized representatives. The text has to be adopted by the
2/3rd of the States present and voting.
Ways of expressing consent
Article 11, VCLT, 1969 lays down certain ways of expressing consent. They are:
4. Exchange of instruments constituting a treaty, approval or accession.
Consent by Signature: Signature gives consent to the text of the agreement where the
circumstances are defined in the treaty
Signature creating Obligations: generally signed at the end of a multilateral convention by
the head of the state in an elaborate ceremony
Signature pending ratification: Interim obligations of good faith- States have to refrain from
acts that would defeat the purpose and object of the treaty.
Consent by ratification: Ratification involves two distinct procedural acts:
1) Internal act of approval
2) International procedure bringing a treaty into force- Article 2(1)(b): the international
act whereby a state establishes on the international plane its consent to be bound by a
The device of ratification was originally devised to ensure that the representative did not
exceed his powers or instructions with regard to the making of a particular agreement.
Originally, it could only be ratified by a sovereign but now it is made subject to the
Article 14, VCLT 1969- Ratification will express a state’s consent to be bound by a treaty
where the treaty so provides, if the negotiating states have signed the treaty subject to
Unless, it is an executive agreement, requirement of ratification is a general rule in the United
States. Ratification is only necessary if it is contemplated by the parties to the treaty in the
UK. Ratification is generally a norm in multi-lateral treaties. The Secretary General of the
United Nations will act as a depository for ratifications.
Accession, Acceptance and Approval:
Accession- A method by which a State becomes a party to a treaty it has not signed earlier.
Multi-lateral treaties provide for the subsequent accession of the States.
Acceptance and Approval- Newer terminologies have evolved; in substance it means
“accession”. The expression “subject to acceptance” is equivalent to “subject to accession”.
Entry into force, Deposit and Registration:
Treaty does not specify any date- presumption is that the treaty comes into force as soon as
all the negotiating States have consented to be bound. Once the treaty is concluded- the
written instrument of ratification, accession etc. are placed in the custody of a depository.
Art.102 of the UN Charter provides as follows:
1.) Every treaty and every international agreement entered into by any Member of the
United Nations after the present Charter comes into force as soon as possible be
registered with the Secretariat and published by it.
2.) No party to any such treaty or international agreement which has not been registered
in accordance with the provisions of paragraph 1 of this Article may invoke that treaty
or agreement before any organ of the United Nations.
2.1.7 RESERVATION TO TREATIES
Art. 2(d) of the Convention defines Reservation as:
a unilateral statement, however phrased or named, made by a state, when signing, ratifying,
accepting, approving or acceding to a treaty, whereby it purports to exclude or to modify the
legal effect of certain provisions of the treaty in their application to that state.
The League of Nations practice in regard to multi-lateral treaties lacked consistency. The
League Secretariat followed the principle of absolute integrity. A reservation would only be
valid if the treaty permitted it or all contracting parties accepted it.
The compatibility test:
The regional organizations like the Pan-American Union adopted a flexible system which
permitted a reserving State to become a party vis-à-vis non-objecting States. A state which
has made a reservation can be regarded as being a party to the Convention if the reservation
is compatible with the object and purpose of the Convention.
ICJ on Genocide Convention Case: Following the adoption of Genocide Convention in
1948, divergence of opinions emerged. The ICJ in its advisory opinion endorsed the
compatibility test. After initial rejection by the ILC, on the request of the General Assembly,
it extended the Compatibility test to cover all UN Conventions. The integrity of the treaty is
intact. Legal effect of reservation is given only after ratification. On ratification, such
reservations become an integral part of the treaty.
Reservations have a legal impact. They are distinct from political manifestations and
interpretative declarations. Reservations are not applicable in bilateral treaties.
Simple Interpretative Declaration- It is just a statement with no legal effect. It cannot be
equated to reservation.
Conditional or qualified Interpretative Declaration- State subjects its consent to be bound by
a treaty to a specific interpretation of the treaty or specific interpretation of a provision of the
Anglo-French Continental Shelf Case, 1979- For Article 6 of the Continental Shelf
Convention, 1958 i.e. the Equidistant Principle: France expressed reservation for Bay of
Granville as area of ‘special circumstances’. UK contended it to be merely interpretative
The Tribunal stated:
Although the reservation contained elements of interpretation, it also constituted a specific
condition imposed by France on its acceptance of the delimitation regime.
It went beyond interpretation as the purpose of seeking to exclude or modify the legal effect
of certain treaty provisions by the reserving state and thus constituted a reservation.
Belilos v Switzerland, ECHR 1988:
Switzerland signed and ratified the European Convention of Human Rights. At the time of
ratification, Switzerland made in total 2 Interpretative Declarations and 2 Reservations.
The Declaration in question in the present case: Article 6(1) of the ECHR- Right of Fair trial
of the accused. Switzerland considers that the right of fair trial is intended solely to ensure
ultimate control by the Judiciary over the acts or decisions of the public authorities.
The basic stance of the Commission: it is simple interpretative declaration and not reservation
because State made both reservations and interpretative declarations at the same time. The
Swiss Government argued that it is qualified interpretative declaration and there was no
reaction from the State parties at the time of ratification, hence, tacit approval.
The Court held that the intention of the State party is material. Mere silence does not mean
acquiescence. The concerned declaration was in the nature of reservation. But, it remains an
invalid reservation as the terms were too vague and general in character, therefore violative
of Article 64 of the Convention.
Reservations that have no legal effect:
1.) Incompatible with the object and purpose of the Treaty (Article 19)
2.) The reservation is specifically prohibited by the Treaty (Article 19)
3.) Derogation from some basic human rights impermissible (Article 53)
4.) Reservation that is too broad or vague and is of general character (Article 64)
Entry into force of treaties:
• Treaties will become operative when and how the negotiating states decide.
• In the absence of any provision to the contrary, a treaty will enter into force as soon as
consent to be bound by the treaty has been established for all the negotiating states.
• Generally, multilateral treaties provide for entry into force upon ratification by a fixed
number of states, since otherwise large multi-lateral treaties might be prejudiced.
General rules of the application of treaties:
• The treaty will ordinarily have a prospective application
• The treaty is binding upon each State party w.r.t its entire territory.
• In case of successive treaties on the same subject matter, the later will prevail in case
2.1.8 THE THIRD STATES
• Article 34: A treaty does not create either obligations or rights for a third state
without its consent.
• One exception to the rule is that where the provision of the treaty in question have
entered into customary law.
• Article 2(6) of the UN Charter: the organization shall ensure that states which are not
members of the United Nations act in accordance with these principles so far as may
be necessary for the maintenance of international peace and security
‘Creation of obligations’ v ‘Creation of rights’-
Creation of Obligations- Article 35 of the VCLT- Express agreement of the State in accepting
the obligation in writing.
Creation of Rights- Article 36 of the VCLT- its assent is presumed as long as the contrary is
2.1.9 THE AMENDMENT AND MODIFICATION OF TREATIES
Amendments refer to formal alteration of treaty provisions affecting all the parties to the
particular agreement. Modification relates to variation of certain treaty norms as between
particular parties only.
Amendment of Treaties:
Alterations require the same legal formalities as in the original formation of the treaty. Any
proposed amendment has to be notified to all the parties. Such amendments will not bind all
States to the original treaty and those who do not want to be party to the amendments. A new
State party will be a party to the new treaty not the original one.
Modification of a treaty:
Parties may decide to change the agreement as between themselves in certain ways, different
from amendment by all the parties. That is possible if it is not affecting the rights of the other
parties. Modification is not possible where there is derogation from the object and purpose of
the treaty as a whole.
2.1.10 TREATY INTERPRETATION
1.) Actual text of the treaty
2.) Intention of the parties adopting the agreement
3.) Object and purpose of the treaty
Natural and ordinary meaning of the words to be analyzed- context is to be taken into
account- principle of ‘contemporaneity’.
Depends upon the nature of the treaty:
• Human rights treaties: flexible approach, interpretation favorable to the individual
• Treaties of Incorporation: dynamic interpretation, to accomplish the aims of the
• Treaties dealing in scientific advancements: principle of contemporaneity, principle
of subsequent developments
2.1.11 INVALIDITY, TERMINATION AND SUSPENSION OF THE OPERATION
Article 44: General Provisions:
Normally, a treaty may be withdrawn as a whole. If parties seek to withdraw only particular
clauses, it is possible only if the said clauses are separable from the remainder of the treaty.
Acceptance of those clauses was not an essential basis of consent of the other party.
Continued performance of the remainder of the treaty would not be unjust.
Invalidity of Treaties
1.) Violations of internal law
2.) Defects of authority
3.) Error- Article 48- error related to a fact or situation which was assumed by the State
to exist. Such error existed at the time of the conclusion of the treaty. Such error
formed the basis of its consent to be bound by the treaty.
4.) Fraud- Article 49- where a State consents to be bound by a treaty as a result of the
fraudulent conduct of another negotiating State- then such consent would be
5.) Corruption- Article 50- when a negotiating State directly or indirectly corrupts the
representative of another State in order to obtain the consent of the latter to the treaty,
then such consent would also be invalidated.
6.) Coercion- Article 51: Acts obtained by coercing the representative of the State by acts
or threats directed against him.
Article 52: A treaty is void if its conclusion has been obtained by the threat or use of
force in violation of international law.
7.) Conflict with a preemptory norm- Article 53, VCLT: A treaty in violation of a
peremptory norm of international law is void.
Consequences of Invalidity:
is void w/out
any legal force
If If a treaty is
nevertheless void under
Each party may Acts performed Parties have to
require other in good faith are eliminate the
party to not rendered the act & align it
establish the unlawful by
reason only of to jus cogens
status quo invalidity
The termination of Treaties:
1.) By Treaty Provision or Consent:
• In accordance to the provisions of the treaty.
• If no specific provision on termination, parties may do so if the right may be implied
by the nature of the treaty.
• A treaty may come to an end when its object and purpose come to an end.
• Where all the parties to a treaty later conclude another agreement relating to the same
subject matter, the earlier treaty may be regarded as terminated if incompatible.
2.) Termination due to material breach:
If a State violates an important provision in an agreement, it is natural for the other states to
regard that agreement ended by it.
By rendering treaties revocable because one party has acted contrary, would place the state
parties in a rather vulnerable position.
When breach of provision which frustrate the object or purpose of the treaty- results in
termination of treaty.
3.) Supervening impossibility of performance:
Article 61: It deals with disappearance or destruction of an object indispensible for the
execution of the treaty. Impossibility has to be concrete and permanent. Impossibility is not
an excuse for the party that has resulted in the impossibility.
4.) Fundamental Change of Circumstances
Article 62: Based on the doctrine of rebus sic stantibus. In the modern times, it has found
acceptance but in a restrictive way only if results in a radical transformation of the extent of
the obligation imposed by it.
The ICJ in the Fisheries Jurisdiction Case:
Before the doctrine may be applied, it is necessary that such changes ‘must have increased
the burden of the obligations to be executed to the extent of rendering the performance
something essentially different from that originally undertaken.’