[Vid Prislan is a Research Fellow PhD-candidate at the Grotius Centre for International Legal Studies of Leiden University]
First of all, I would like to thank the editors of
Opinio Juris for providing me with the opportunity to briefly present the arguments which I raise in my chapter in
Investment Law within International Law: Integrationist Perspectives.
My chapter deals very broadly with the issue of non-investment obligations in investment treaty arbitration. It does so by exploring how investment tribunals can consider (and take into account) arguments based on sources of obligations other than those under investment treaties.
The possibility of considering non-investment obligations has occasionally been questioned by reference to the limited jurisdictional competence of investment tribunals. Indeed, the jurisdiction of these tribunals is not unqualified, but limited by the extent to which the States assented to it in the underlying investment treaty – that is, potentially confined only to pronouncing upon alleged violations of the substantive rights under the treaty. Yet, I argue, first of all, that jurisdictional limitations do not necessarily restrict the scope of the law applicable to the dispute. In most cases, in fact, investment tribunals will enjoy broad latitude with regard to the scope of the legal rules that they are entitled to apply, which makes it possible for them to consider, and indeed apply, obligations other than those under the treaty. Second, I contend that investment agreements were not conceived as self-contained regimes, and therefore, cannot be applied in isolation of other rules and principles of international law. In particular, I argue that, at the very least, rules of customary international law, as well as general principles of law remain applicable, to the extent that their application has not been excluded by the investment treaty as
lex specialis.
Even if one accepts that jurisdictional limitations potentially prevent investment tribunals from directly adjudicating upon claims based on non-investment obligations, there is no impediment for investment tribunals to consider these rules when constructing the meaning of the substantive protections laid down in an investment treaty. I suggest that some of the jurisdictional limitations may be overcome by taking account of non-investment obligations in the process of
interpreting the provisions of the investment treaty. I focus specifically on three interpretative techniques that can be applied by investment tribunals for this purpose.
