Part 2 Practical Significance, 9 Subsequent Agreements and Practice: The Battle over Interpretive Power

Subsequent agreements and practices are important mechanisms by which treaty parties can assert their continued interpretive authority over treaties without having to amend those treaties. States are masters of their treaties not only in the sense that they can enter into and exit from such treaties, but also because the Vienna Convention on the Law of Treaties requires that treaties be interpreted in light of the treaty parties’ subsequent agreements and practices that are relevant to interpretation.1 This provision recognizes the significant and ongoing role...