Normative conflicts in international investment law: the case of environmental law

This dissertation investigates the relationship between investment and environmental obligations from the perspective of international investment law. In order to do so, the dissertation will consider how these obligations might enter into conflicts and what tools are available to investment tribunals to solve these normative conflicts. The dissertation analyses in order interpretative techniques, conflict resolution tools available in general international law, as expressed in the Vienna Convention on the Law of Treaties, and finally express clauses in international investment agreements. The dissertation includes the review of some relevant case law arising from investment agreements in investment treaty tribunals, to discover how in practice these conflict resolution tools are applied and to assess their effectiveness. This dissertation places itself squarely within the debate between the unity and the fragmentation of international law; therefore it tackles the issue of normative conflicts resolution in a dispute settlement environment with the view of gauging their value in maintaining the unity of international law and defuse the risk of fragmentation. The dissertation can only conclude that much work remains to be done, including by providing a more comprehensive taxonomy of possible interventions, both on the legal and political sphere.