Section 4. Treaties and third States

Article 34 General rule regarding third States
A treaty does not create either obligations or rights for a third State without its consent.

Article 35 Treaties providing for obligations for third States
An obligation arises for a third State from a provision of a treaty if the parties to the treaty intend the provision to be the means of establishing the obligation and the third State expressly accepts that obligation in writing.

Article 36 Treaties providing for rights for third States
1. A right arises for a third State from a provision of a treaty if the parties to the treaty intend the provision to accord that right either to the third State, or to a group of States to which it belongs, or to all States, and the third State assents thereto. Its assent shall be presumed so long as the contrary is not indicated, unless the treaty otherwise provides.
2. A State exercising a right in accordance with paragraph 1 shall comply with the conditions for its exercise provided for in the treaty or established in conformity with the treaty.

Article 37 Revocation or modification of obligations or rights of third States
1. When an obligation has arisen for a third State in conformity with article 35, the obligation may be revoked or modified only with the consent of the parties to the treaty and of the third State, unless it is established that they had otherwise agreed.
2. When a right has arisen for a third State in conformity with article 36, the right may not be revoked or modified by the parties if it is established that the right was intended not to be revocable or subject to modification without the consent of the third State.

Article 38 Rules in a treaty becoming binding on third States through international custom
Nothing in articles 34 to 37 precludes a rule set forth in a treaty from becoming binding upon a third State as a customary rule of international law, recognized as such.


Part IV Amendment and modification of treaties

Article 39 General rule regarding the amendment of treaties
A treaty may be amended by agreement between the parties. The rules laid down in Part II apply to such an agreement except in so far as the treaty may otherwise provide.

Article 40 Amendment of multilateral treaties

1. Unless the treaty otherwise provides, the amendment of multilateral treaties shall be governed by the following paragraphs.
2. Any proposal to amend a multilateral treaty as between all the parties must be notified to all the contracting States, each one of which shall have the right to take part in:
(a) the decision as to the action to be taken in regard to such proposal;
(b) the negotiation and conclusion of any agreement for the amendment of the treaty.
3. Every State entitled to become a party to the treaty shall also be entitled to become a party to the treaty as amended.
4. The amending agreement does not bind any State already a party to the treaty which does not become a party to the amending agreement; article 30, paragraph 4(b), applies in relation to such State.
5. Any State which becomes a party to the treaty after the entry into force of the amending agreement shall, failing an expression of a different intention by that State:
(a) be considered as a party to the treaty as amended; and
(b) be considered as a party to the unamended treaty in relation to any party to the treaty not bound by the amending agreement.

Article 41 Agreements to modify multilateral treaties between certain of the parties only

1. Two or more of the parties to a multilateral treaty may conclude an agreement to modify the treaty as between themselves alone if:
(a) the possibility of such a modification is provided for by the treaty; or
(b) the modification in question is not prohibited by the treaty and:

(i) does not affect the enjoyment by the other parties of their rights under the treaty or the performance of their obligations;
(ii) does not relate to a provision, derogation from which is incompatible with the effective execution of the object and purpose of the treaty as a whole.
2. Unless in a case falling under paragraph 1(a) the treaty otherwise provides, the parties in question shall notify the other parties of their intention to conclude the agreement and of the modification to the treaty for which it provides.


Part V Invalidity, termination and suspension of the operation of treaties

Section 1. General provisions

Article 42 Validity and continuance in force of treaties

1. The validity of a treaty or of the consent of a State to be bound by a treaty may be impeached only through the application of the present Convention.
2. The termination of a treaty, its denunciation or the withdrawal of a party, may take place only as a result of the application of the provisions of the treaty or of the present Convention. The same rule applies to suspension of the operation of a treaty.

Article 43 Obligations imposed by international law independently of a treaty

The invalidity, termination or denunciation of a treaty, the withdrawal of a party from it, or the suspension of its operation, as a result of the application of the present Convention or of the provisions of the treaty, shall not in any way impair the duty of any State to fulfil any obligation embodied in the treaty to which it would be subject under international law independently of the treaty.

Article 44 Separability of treaty provisions

1. A right of a party, provided for in a treaty or arising under article 56, to denounce, withdraw from or suspend the operation of the treaty may be exercised only with respect to the whole treaty unless the treaty otherwise provides or the parties otherwise agree.
2. A ground for invalidating, terminating, withdrawing from or suspending the operation of a treaty recognized in the present Convention may be invoked only with respect to the whole treaty except as provided in the following paragraphs or in article 60.
3. If the ground relates solely to particular clauses, it may be invoked only with respect to those clauses where:
(a) the said clauses are separable from the remainder of the treaty with regard to their application;
(b) it appears from the treaty or is otherwise established that acceptance of those clauses was not an essential basis of the consent of the other party or parties to be bound by the treaty as a whole; and
(c) continued performance of the remainder of the treaty would not be unjust.
4. In cases falling under articles 49 and 50 the State entitled to invoke the fraud or corruption may do so with respect either to the whole treaty or, subject to paragraph 3, to the particular clauses alone.
5. In cases falling under articles 51, 52 and 53, no separation of the provisions of the treaty is permitted.

Article 45 Loss of a right to invoke a ground for invalidating, terminating, withdrawing from or suspending the operation of a treaty

A State may no longer invoke a ground for invalidating, terminating, withdrawing from or suspending the operation of a treaty under articles 46 to 50 or articles 60 and 62 if, after becoming aware of the facts:
(a) it shall have expressly agreed that the treaty is valid or remains in force or continues in operation, as the case may be; or
(b) it must by reason of its conduct be considered as having acquiesced in the validity of the treaty or in its maintenance in force or in operation, as the case may be.


Section 2: Invalidity of treaties

Article 46 Provisions of internal law regarding competence to conclude treaties
1. A State may not invoke the fact that its consent to be bound by a treaty has been expressed in violation of a provision of its internal law regarding competence to conclude treaties as invalidating its consent unless that violation was manifest and concerned a rule of its internal law of fundamental importance.
2. A violation is manifest if it would be objectively evident to any State conducting itself in the matter in accordance with normal practice and in good faith.

Article 47 Specific restrictions on authority to express the consent of a State
If the authority of a representative to express the consent of a State to be bound by a particular treaty has been made subject to a specific restriction, his omission to observe that restriction may not be invoked as invalidating the consent expressed by him unless the restriction was notified to the other negotiating States prior to his expressing such consent.

Article 48 Error
1. A State may invoke an error in a treaty as invalidating its consent to be bound by the treaty 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.
2. Paragraph 1 shall not apply if the State in question contributed by its own conduct to the error or if the circumstances were such as to put that State on notice of a possible error.
3. An error relating only to the wording of the text of a treaty does not affect its validity; article 79 then applies.

Article 49 Fraud
If a State has been induced to conclude a treaty by the fraudulent conduct of another negotiating State, the State may invoke the fraud as invalidating its consent to be bound by the treaty.

Article 50 Corruption of a representative of a State
If the expression of a State's consent to be bound by a treaty has been procured through the corruption of its representative directly or indirectly by another negotiating State, the State may invoke such corruption as invalidating its consent to be bound by the treaty.

Article 51 Coercion of a representative of a State
The expression of a State's consent to be bound by a treaty which has been procured by the coercion of its representative through acts or threats directed against him shall be without any legal effect.

Article 52 Coercion of a State by the threat or use of force
A treaty is void if its conclusion has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations.

Article 53 Treaties conflicting with a peremptory norm of general international law (jus cogens)

A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law. For the purposes of the present Convention, a peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.


Section 3: Termination and suspension of the operation of treaties

Article 54 Termination of or withdrawal from a treaty under its provisions or by consent of the parties

The termination of a treaty or the withdrawal of a party may take place:
(a) in conformity with the provisions of the treaty; or
(b) at any time by consent of all the parties after consultation with the other contracting States

Article 55 Reduction of the parties to a multilateral treaty below the number necessary for its entry into force
Unless the treaty otherwise provides, a multilateral treaty does not terminate by reason only of the fact that the number of the parties falls below the number necessary for its entry into force.

Article 56 Denunciation of or withdrawal from a treaty containing no provision regarding termination, denunciation or withdrawal
1. A treaty which contains no provision regarding its termination and which does not provide for denunciation or withdrawal is not subject to denunciation or withdrawal unless:
(a) it is established that the parties intended to admit the possibility of denunciation or withdrawal; or
(b) a right of denunciation or withdrawal may be implied by the nature of the treaty.
2. A party shall give not less than twelve months' notice of its intention to denounce or withdraw from a treaty under paragraph 1.

Article 57 Suspension of the operation of a treaty under its provisions or by consent of the parties

The operation of a treaty in regard to all the parties or to a particular party may be suspended:
(a) in conformity with the provisions of the treaty; or
(b) at any time by consent of all the parties after consultation with the other contracting States.

Article 58 Suspension of the operation of a multilateral treaty by agreement between certain of the parties only

1. Two or more parties to a multilateral treaty may conclude an agreement to suspend the operation of provisions of the treaty, temporarily and as between themselves alone, if:
(a)
the possibility of such a suspension is provided for by the treaty; or
(b) the suspension in question is not prohibited by the treaty and:
(i) does not affect the enjoyment by the other parties of their rights under the treaty or the performance of their obligations;
(ii) is not incompatible with the object and purpose of the treaty.
2. Unless in a case falling under paragraph 1(a) the treaty otherwise provides, the parties in question shall notify the other parties of their intention to conclude the agreement and of those provisions of the treaty the operation of which they intend to suspend.

Article 59 Termination or suspension of the operation of a treaty implied by conclusion of a later treaty

1. A treaty shall be considered as terminated if all the parties to it conclude a later treaty relating to the same subject-matter and:
(a) it appears from the later treaty or is otherwise established that the parties intended that the matter should be governed by that treaty; or
(b) the provisions of the later treaty are so far incompatible with those of the earlier one that the two treaties are not capable of being applied at the same time.
2. The earlier treaty shall be considered as only suspended in operation if it appears from the later treaty or is otherwise established that such was the intention of the parties.

Article 60 Termination or suspension of the operation of a treaty as a consequence of its breach

1. A material breach of a bilateral treaty by one of the parties entitles the other to invoke the breach as a ground for terminating the treaty or suspending its operation in whole or in part.
2. A material breach of a multilateral treaty by one of the parties entitles:
(a) the other parties by unanimous agreement to suspend the operation of the treaty in whole or in part or to terminate it either:
(i) in the relations between themselves and the defaulting State, or
(ii) as between all the parties;
(b) a party specially affected by the breach to invoke it as a ground for suspending the operation of the treaty in whole or in part in the relations between itself and the defaulting State;
(c) any party other than the defaulting State to invoke the breach as a ground for suspending the operation of the treaty in whole or in part with respect to itself if the treaty is of such a character that a material breach of its provisions by one party radically changes the position of every party with respect to the further performance of its obligations under the treaty.
3. A material breach of a treaty, for the purposes of this article, consists in:
(a) a repudiation of the treaty not sanctioned by the present Convention; or
(b) the violation of a provision essential to the accomplishment of the object or purpose of the treaty.
4. The foregoing paragraphs are without prejudice to any provision in the treaty applicable in the event of a breach.
5. Paragraphs 1 to 3 do not apply to provisions relating to the protection of the human person contained in treaties of a humanitarian character, in particular to provisions prohibiting any form of reprisals against persons protected by such treaties.