Interplays between international and domestic legal spheres have attracted increased attention in investor-State dispute settlement. From the treaty ratification process to award execution, constitutional norms play recurring roles before, during and after investment arbitrations. This contribution deals with the manner in which parties to such disputes can rely upon constitutional law or, more broadly speaking, domestic law. Notably, major hurdles to the application of domestic law in transnational fora have not necessarily constrained the arbitral profile of constitutional principles. This is because they may gain prominence through informal paths. Rather than directly applying constitutional law per se, tribunals may utilize other paths such as deferring to domestic interpretations of constitutional principles, or to constitutional procedures that appear, for example, to protect fair and equitable treatment. Reexamining recent case law through this lens of informal application, we can then envision other synergies that intermingle these regimes.
Klägersupra note 35 pp. 236–237. This function of proportionality may have originated in the administrative law of Germany. The concept has since developed into a doctrinal element of constitutional law in that State.
Boisson de Chazournessupra note 1 p. 321.
Ulfsteinsupra note 94 p. 126.
Monttsupra note 35 p. 12.
Klägersupra note 35 p. 134.
Schillsupra note 101 pp. 91–92.
Monttsupra note 35 p. 158.
Schillsupra note 114 pp. 901–902 (advocating broad recourse to proportionality analysis and echoing Ernst-Ulrich Petersmann ‘Introduction and Summary: ‘Administration of Justice’ in International Investment Law and Adjudication?’ in P.-M. Dupuy E.-U. Petersmann and F. Francioni (eds.) Human Rights in International Investment Law and Arbitration (oup 2009) 3 42).
Tanzisupra note 27 pp. 65–67 (stating the need for a balanced approach to economic and public welfare interests) 75–76 (supporting the ‘principle of harmonization’ as enunciated in Report of the Study Group of the International Law Commission [ilc] ‘Fragmentation of International Law: Difficulties arising from the Diversification and Expansion of International Law’ un Doc. A/cn.4/L.702 (18 July 2006) para. 229).