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Tanya Agarwal, 3rd Year Ba. LLB (Hons), Amity Law School, Delhi (GGSIPU). The following article explores the relationship between conventions that forms the basis of international law in the form of treaties which governs the relationship between states.


Treaties have been the part of world community since time immemorial, they have been used by various kings, princes, states as a way of establishing peaceful pacts. Article 38 of the ICJ statute dictates treaties to be one of the important sources of International Law. Treaties are considered to be a formal and direct source of International Law which regulates the behaviour and relationships between nations. Majority of conduct between states are governed by the nature of the Treaty device which provides for the rights and obligations of the parties forming part of the treaties.

Definition and conclusion of Treaties

Treaties are nothing but an agreement between the states that are entered mutually, they can also be referred to as agreement, convention, protocol, charter, Pact, Protocol or concordat. An International Convention on the Law of Treaties was signed in 1969 and came into force in 1980, while a Convention on Treaties between States and International Organisations was signed in 1986. Definition of the term “Treaty” as given under Section 2(1)(a) of Vienna convention on the law of treaties is that it means an international agreement concluded between States in written form and governed by international law.

Vienna convention on the law of treaties, 1969 is commonly referred to as “treaty on treaties,” that forms an essential part of customary International Law which provides for the basic framework regarding the characteristics and behaviour of treaties. It defines a treaty and relates to how treaties are made, amended, interpreted, how they operate and are terminated. It does not aim to create specific substantive rights or obligations for parties – this is left to the specific treaty.

They can take various forms which have been confirmed by the ICJ in the Case Concerning Maritime Delimitation and Territorial Questions between Qatar and Bahrain (Qatar vs Bahrain) where it explained the relationship between the “minutes of the meeting” and the character of the treaty under Article 2(1) (a) of the VCLT. Treaties are binding in nature and it provides the parties to follow their obligations in good faith. Treaties can be between two parties that is Bilateral or more than two parties that is multilateral. Here

Treaties are binding but they do not create any legal obligation as to its each and every provision, their main intention is to create legal relations between parties to regulate their relationship through an agreement. Treaty is a formal document which goes through several steps before its conclusion which are as follows:

1. Negotiation

The intention of the parties involved in dictating the terms of the treaty decides its nature, these parties can be Government, States, Head of States or Government Departments. It often undergoes several negotiations before it becomes a formal document. The duty to regulate the formation of a treaty is handed over to the Executive branch of the state.  Article 8 of VCLT states that any action relating to the making of a treaty by a person not authorised as required will be without any legal effect unless the state involved afterwards confirms the act.

All the parties involved, negotiate and try to find common grounds for coming to an agreement. It is also to be noted, that not only the parties involved in the negotiations form part of the treaty but other states can also enter the same later through “Accession.” After negotiations, the next step requires the consent of all the parties which have their vested interest in it.

2. Consent

Treaties are binding in nature which creates rights and obligations for states in the international community, therefore consent is a very important step as it may bind the states to follow and uphold the said treaty. Article 9 of VCLT provides two ways by which a treaty is adopted that is through consent which includes consent of all the parties participating in its formation or adoption in international conferences which takes place by a vote of two-thirds of the state’s present and voting unless by the same majority it is decided to apply a different rule.

Treaties are a major document and there are various ways by which states can give consent so that a treaty can come into existence, as per Article 11 of VCLT it includes, consent by signature, exchange of instruments constituting a treaty, ratification, acceptance, approval or accession, or by any other means if so agreed.

Consent by Signature:

It is to be noted as per Article 12 of the VCLT, three conditions have been laid out as to when the signature to the treaty leads to consent which is as follows:

  1. It is provided in the treaty itself that signature shall take effect.
  2. It is agreed by the state during the negotiation that states signature shall take effect.
  3. The intention of the State to give  effect to the signature appears from the full powers of its representation or during the negotiation.

The act of signing a treaty is a very significant step which needs to be conducted cautiously, the duty shall be given to a proper formal authority like the head of the state or its representatives to sign the same.

Consent by the exchange of Instruments

According to Article 13 of the VCLT, in case of treaties which are expressed through any instrument that is exchanged between the consenting parties, it may be expressed by a declaration made in the instrument giving effect or otherwise establishing that those states had agreed that the exchange of instruments should have that effect.

3. Signature Followed By ratification

Once the consent is given to a treaty, the next step is its ratification which officially declares that a treaty is in effect between the concerned parties. Ratification of a treaty leads to the creation of formal obligations and rights. The signing of a treaty does not lead to its automatic ratification, it should be acknowledged by proper authority. It is important to understand the gap between the ratification and signature, it is there to encourage public opinion as more time ensures that the treaty is also beneficial for the state in the eyes of the public.

The process of ratifying a treaty differs from state to state however in Article 14 of the VCLT certain conditions are given which leads ratification of a treaty which are as follows:

  • When the treaty provides for the expression of consent by means of ratification.
  • During the negotiation, the states agree for ratification
  • The treaty is signed subject to ratification
  • There is an intention to ratify the treaty by the representative of the state

It is mainly up to the provisions of the treaty which dictates the status of the parties after its ratification.


Reservation to a treaty is given under Article 2(d) of VCLT defining ‘reservation’ as a  unilateral statement, 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. 

Reservation allows states to have a way of consenting to those provisions which are beneficial to them and reject other provision of the treaty. With the help of these, states have a way of excluding the legal effects of those provisions of the treaty which it objects. A state can exercise the privilege of reservation only before finalising the treaty, once a treaty is signed it can be reserved later on.

It promotes more participation from the states in the international community especially in cases of the multinational treaty by giving them an opportunity to agree and disagree as to their preferred obligations.

A test has been laid down to analyse the practice of reservation to a treaty which includes determining the substance of the interpretative declaration given by the state that is, one has to look into the declaration and interpret its word as to whether the intention behind it includes reservation state.

In the Anglo-French continental shelf case, the arbitral tribunal adjudged that the acceptance of France through an interpretive declaration to Article 6 of the Geneva Convention on the Continental Shelf involved laying down of a specific condition. It, therefore, had the purpose of seeking to exclude or modify the legal effect of certain treaty provisions with regard to their application by the reserving state and thus constituted a reservation.

In another case adjudged by the European Court of Human Rights that is Belilos Case, it was stated that substantive content of the declaration is necessary to understand the intention of the state.

Therefore, in order to determine whether a unilateral statement made constitutes a reservation or an interpretative declaration, it is necessary to interpret the ordinary meaning of the statement. The consent of all the states participating in the treaty is necessary to be considered before reserving to a treaty.

The procedure by which states can reserve to treaty is prescribed under Article 19 of the VCLT, according to which it can be done by signing, ratifying, accepting, approving or acceding to a treaty, but they cannot be made where the reservation is prohibited by the treaty, or where the treaty provides that only specified reservations may be made and these do not include the reservation in question, or where the reservation is not compatible with the object and purpose of the treaty. 

Section 2 of the Vienna Convention on the law of treaties provides for the rules to be followed during the reservation of a treaty, as per it the relationship of the contracting states changes according to their reservation. It is also up to the treaty to allow for a particular reservation if it does not allow the same it may depend upon the behaviour of the other states.

In the case of Human rights treaties, it has been noted that reservations are generally impermissible so as to apply the full effects of the provisions of the treaties. Reservations to a multilateral treaty may be withdrawn, subject to agreement to the contrary, only when the other states to the treaty have received notification of that withdrawal.

Observance of treaties

Part 3 of the Vienna Convention of the law of treaties deals with the rules regarding the observance of the treaty which comes up once the treaty has been finalised and ratified by the states. Following rules are observed under the aforesaid section of the VCLT:

a. Pacta sunt sarvanda

It is the customary rule of International law that treaties should be performed by the states in good faith which is also evident in the United Nations Charter under Article 2 which states that Members are required to perform their obligations in good faith as stated in the charter. The principle is based on the most basic fundamental rule of International law that treaties are meant to be performed by the ratifying states and it should be taken care that states do not take their international obligations lightly.

b. The territorial scope of treaties

As provided under Article 29 of the VCLT a treaty is binding upon the entire territory of each party unless it is provided under the treaty for its restricted application.

c.  Interpretation of treaties

Article 31 to Article 33 of the Vienna Convention of the law of treaties dictate the rules regarding the interpretation of the treaties which can be summarized into three rules that are:

  1. Analysing the actual text of the agreement.
  2. The intention of the parties negotiating on the treaty.
  3. Consideration of the object and purpose of the treaty.

The international court of justice in the case of Competence of the General Assembly for the Admission of a State to the United Nations noted that the duty of the tribunal is to look into the ordinary meaning of the treaty. It has also been noted by the international court that the process of interpretation ‘is a judicial function, whose purpose is to determine the precise meaning of a provision, but which cannot change it.’ Analyzing the background of the workings of a treaty and its preparatory works (travaux pr´eparatoires) can help in interpretation of the treaty.

Where a treaty is authenticated in more than one language, as often happens with multilateral agreements, Article 33 provides that, in the absence of agreement, in the event of a difference of meaning that the normal processes of interpretation cannot resolve, the meaning which best reconciles the texts, having regard to the object and purpose of the treaty, shall be adopted.

d. Treaties and the third state

The general rule of treaties is that they are binding only to the states that are party to it and not to any third member. Therefore, it cannot create an obligation on another state however there is one major exception to this rule which covers the area of customary international law that is if a treaty forms part of customary international law than it is the duty of the states not to violate it.

As per Article 35 of the VCLT, an obligation may arise for the third state if the provisions of the treaty on express written opinion of the parties to the treaty create an obligation for another state and the state gives its consent for the same which has been referred by the ICJ in the Free Zones case that it is the intention of the states that have to be considered.

Invalidity, termination and suspension of the treaty

Vienna convention on the law of treaties provides a list of exhaustive rules under which a treaty can be terminated however, it is necessary to distinguish between the rules of termination and grounds for non-performance of a treaty. Following are the grounds for termination of a treaty:

1. Invalidity

Under article 42 the consent to abide by the treaty in force is presumed by the states however there are certain grounds which can invoke its invalidity which are:

a.  Violation of an internal law

It should be noted that a state may not invoke a provision of its internal law as a justification for its failure to carry out an international obligation. This is a general principle of international law but if it violates a fundamental law than as per Article 46 it can invalidate a treaty.

b. Error

Article 48 declares that a state may only invoke an error in a treaty as invalidating if the error relates to a fact or situation which was assumed by that State to exist at the time when the treaty was concluded and formed an essential basis of its consent to be bound by the treaty. This restrictive approach is in harmony with the comments made in a number of cases, including the Temple case by the ICJ where it noted that in view of the character and qualifications of the persons who were involved on the Thai side in examining the map, Thailand could not put forward a claim of error.

c.  Fraud, Corruption and Coercion

d. Conflict with a peremptory norm

VCLT Article 53 provides that a treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law (jus cogens). Further, a treaty becomes void if it conflicts with a peremptory norm of general international law established after the treaty comes into force.

2. Termination

VCLT Part V Section 3 deals with termination and suspension of the operation of treaties. A treaty may, of course, specify the conditions of its termination and may provide for denunciation by the parties. Where a treaty contains no provisions regarding its termination, the existence of a right of denunciation depends on the intention of the parties, which can be inferred from the terms of the treaty and its subject-matter, but, according to the VCLT, the presumption is that the treaty is not subject to denunciation or withdrawal.

At least in certain circumstances, denunciation is conditional upon a reasonable period of notice. Some important law-making treaties contain no denunciation clause. Treaty of peace is not open to unilateral denunciation. Following are the grounds of the termination and suspension of a treaty:

  • Material breach
  • Treaty provision and consent
  • The fundamental change of circumstances.

3. Procedure and consequence of the termination

The consequences of invalidity, termination, and suspension will depend on the grounds relied upon. Certain grounds of invalidity must be invoked by a party and so the treaties concerned are not void but voidable. 

These grounds are incompetence under internal law, restrictions on the authority of representative, error, fraud, and corruption of a representative.

The same is true of certain grounds of termination—material breach, impossibility and fundamental change of circumstances. On the other hand, a treaty is void in case of coercion of a state (invalidity), and conflict with an existing or emergent peremptory norm (invalidity or termination). Consent to be bound by a treaty procured by the coercion of the representative of a state ‘shall be without any legal effect’ (Article 51, invalidity).

The rules governing separability of treaty provisions (Article 44), that is, the severance of particular clauses affected by grounds for invalidating or terminating a treaty, do not apply to the cases of coercion of a representative, coercion of a state, or conflict with an existing peremptory norm. Articles 69 to 72 deal with the consequences of invalidity, termination, or suspension.


Vienna Convention on the Law of Treaties is a comprehensive code that codifies the relationship between the states and a treaty. It includes the framework regarding the conclusion, observance and interpretation of the treaty. It also dictates various grounds for terminating a treaty and the procedure to be followed after that. Generally, it is considered that a treaty may enter into force after it has been signed and ratified. Parties to a treaty may exercise the right of the reservation to preserve their interest. The purpose of the Law of Treaties is to expand and develop a friendly relationship between nations and achieve cooperation amongst them.


  1. ICJ Reports, 1950, pp. 4, 8.
  6. Draft guideline 1.3.1 of the ILC Guide to Practice, A/61/10, 2006, pp. 327 ff
  7.  Y. Tyagi, ‘The Conflict of Law and Policy on Reservations to Human Rights Treaties’, 71 BYIL, 2000, p. 181.
  9. Ruwanthika Gunaratne, Law of treaties: Vienna convention on the law of treaties

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