Treaty-text Loyalists’ Burden with Subsequent State Practice

The role of subsequent state practice in the procedural law of treaties, and in the determination of consent in the implementation of treaties have become the subject of much scholarly debate in recent times. The UN International Law Commission has devoted copious amounts of study time into these issues under the distinguished guidance of Georg Nolte as Special Rapporteur. Ph.D. theses and research monographs, journal articles and commentaries have appeared on the matter, but the debate persists. At one end of this debate are treaty-text loyalists that reject the potential of subsequent state practice to modify what they regard as ‘solemn oaths’ taken by states when they conclude and adopt a treaty. That ‘temporal declaration of consent’ by states to be bound by a treaty regime is for them sacrosanct. At the other end are analytical jurisprudence scholars who appear to insist upon a purpose test approach to the matter. This article evaluates treaty-text loyalists’ arguments under current state practice on treaty implementation across a number of disciplines. It shows that the view that ‘temporal consent’ supremely prohibits the modification of treaties through subsequent state practice is exaggerated. Moreover, the ‘solemn oaths’ perception of treaties is not supported by recent examples of treaty implementation.