ABSTRACT
a formal change in a treaty intended to alter its provisions with respect to all the parties. Modification, dealt with in Article 41, indicates an inter se agreement concluded between certain of the parties only, and intended to alter the provisions of the treaty between themselves alone. Modification is only allowed if: (1) it is permitted by the treaty; (2) it is not prohibited by the treaty; (3) it does not affect the other parties to the treaty; (4) it is not incompatible with the treaty. More usually amendment or modification is achieved in the case of multilateral treaties by another multilateral treaty which comes into force only for those states which agree to the changes.
