Enforcing Soft Law in International Investment Arbitration

Drawing examples from international environmental law, sustainable development, and corporate social responsibility, this Article examines the evolving role of international investment arbitration in the enforcement of non-binding soft law rules of international law. In doing so, the Article explains how investment tribunals can, and have been called upon to, interpret and, paradoxically, enforce soft law instruments. The Article calls for reevaluation of the nature of soft law and the role of investor-state dispute settlement in international rulemaking and enforcement. It also argues that for international environmental law and law on sustainable development, where the lack of an enforcement mechanism has long been identified as the single major weakness of the system, investor-state dispute settlement might be a viable option for increasing compliance with and enforcement of international law obligations of the sovereign states.