- International investment law — Customary international law — General principles of international law — Arbitral tribunals
This concluding chapter argues that tribunals should make use of general principles of law (GPL) in a manner that goes beyond the traditional functions that are typically identified in doctrine. Thus, GPL should not just be used as ‘gap-filling’ whenever treaty provisions or rules of customary international law do not provide a solution to a particular issue. They should also not be simply used to provide guidance for the interpretation and application of vague or uncertain terms contained in treaties. GPL could be used by tribunals to improve the outcome of decision making by achieving a better balance between investors' rights and States' public interests that is acceptable to all different stakeholders in the process. In other words, GPL should play an important and positive role in the process of recalibrating international investment law in reaction to the current backlash against the legitimacy of the system perceived by some as inherently favourable to the interests of foreign corporations.