Foreign investors’ due dilligence

One of the main traits of international investment law is the way in which, based on its language, structure and operation, it is designed to offer greater tools for foreign investors. Hence, the relations derived from it are asymmetrical, benefiting investors to a large extent and leaving States with few tools, particularly in the framework of international investment arbitration. However, a concept that has been used on some occasions and that has served as a tool for the defense of States is the investor’s due diligence. However, it is a dissimilar and largely indeterminate notion. This article proposes, on the basis of a theoretical, doctrinal and "jurisprudential" study, to define investor due diligence as a multilevel hybrid concept from which clear and enforceable obligations are derived for investors with respect to themselves, host States and the individuals affected by their investments.