In a context of neoliberal globalization, have the processes of elaboration and implementation of foreign investors’ responsibilities by intergovernmental organizations reached the realm of legality? Using an analytical framework and a methodology that combines international law with international relations, this book provides a twofold answer to this question. First, it demonstrates that the normative integration of foreign investors’ responsibilities in international investment law is fragmented and consistent with the interests of the most powerful actors. Second, while using the interactional theory of international law to assess the normative character of several international instruments elaborated and implemented by intergovernmental organizations, it highlights the sense of obligation that each instrument generates. The analysis demonstrates that such a codification process is marked by relations of power and has resulted in several social norms, with relatively few legal norms.