Resolving Treaty Conflicts

Abstract

If treaties do not hang together, then the international legal system will fall apart. But as treaties proliferate, they increasingly overlap and frustrate each other's goals. This article assesses whether there are effective rules and tools that policymakers can use to avert or resolve treaty conflicts in general, regardless of the specific policy-areas at issue. It finds that the Vienna Convention on the Law of Treaties (VCLT) neither addresses the types of conflicts that are relevant today nor is it successful in resolving certain types of conflicts it does address. In order to be a more coherent system, international law needs rules and procedures that assist States in avoiding or resolving treaty conflicts in a principled manner, without necessarily having to resort to international tribunals. This requires more than just a revision of the VCLT but rather a more rigorous approach to envisioning how treaties affect one another, a practice of drafting treaty clauses that takes this interplay into account, a purposive method of treaty interpretation that will better spot potential conflicts, and the acceptance and application of "default rules" in cases of conflict.

The article has five main parts. Part I sets out a typology of treaty conflicts. Part II describes classic methods of conflict avoidance and resolution and how these norms have not been applied consistently and are of little use in the types of conflicts that are now common. Part III assesses the VCLT and shows, through recent examples from a variety of substantive areas, that the VCLT is not equipped for the types of problems States face today. Part IV reconsiders what one may learn from analogies to contractual and legislative conflicts. Part V draws from the previous sections to suggest options in addressing treaty conflicts and considers the implications of the preceding discussion on the status of international law as a coherent legal system.