Aust's Modern Treaty Law and Practice

The issue of successive treaties arises where all or some of the parties conclude a later treaty relating to the same subject matter. The relevant rules of the Vienna Convention on the Law of Treaties are in Articles 30 and 59, which have to be read together. The chapter analyses how these rules might apply. In the case of bilateral treaties, the parties will often include express provisions to clarify the position in respect of an earlier treaty. If not, it may be possible to resolve any inconsistency by interpretation of the two treaties, or the earlier treaty may be treated as terminated or suspended in accordance with Article 59. Or the residual rules of Article 30 may apply, by which the earlier treaty may apply only to the extent that its provisions are compatible with a later treaty. The principles are the same in respect of multilateral treaties but there is a greater variety of express provisions, which are not always clear. The fact that all the parties to an earlier treaty may not be parties to a later treaty also adds complexity. These issues are analysed, together with the residual rules of Article 30.