The Obligation not to Defeat the raison d’être of a Treaty: The Legal Nature of Article 18 VCLT and New Developments in the Law of Treaties
This research focuses on the obligations of States in the time interval between signing or ratifying a treaty and the entry into force of the treaty. This matter is regulated by Article 18 of the Vienna Convention on the Law of Treaties, which imposes an obligation on States not to defeat the object and purpose of a treaty prior to its entry into force when: (a) it has signed the treaty or; (b) it has expressed its consent to be bound by the treaty, pending the entry into force of the treaty and provided that such entry into force is not unduly delayed. However, State and judicial practice is fragmentary and inconclusive in this regard, and since Article 18 expresses a rule of generality and abstraction and does not define its own contours, it continues to be a rich source for uncertainties. This research therefore provides an answer to what the legal character, scope and content of Article 18 VCLT is, with a particular focus on environmental law treaties, investment treaties, and human rights treaties. It do so by bringing together two forms of methodologies; one doctrinal method and one qualitative empirical legal method.