(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
Falidity and continuance in force of treaties
1. The validity of a treaty or of the consent of a State or an international organization 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 or of any international organization to
