Property Rights in Treaty Cases: Lessons for Investor-State Arbitration from Case A15 (II:A) of the Iran-United States Claims Tribunal

On 10 March 2020, the Iran-United States Claims Tribunal (IUSCT) rendered its partial award No. 604-A15 (II:A)/A26 (IV)/B43-FT in Case No. A15 (II:A), ordering the United States to pay Iran over USD 29 million in damages, including decades of interest, and to return several properties that had been frozen during the 1979 hostage crisis. In deciding which properties had to be transferred by the United States to Iran, the Tribunal – having concluded that there are no public international law rules on property – struggled to identify the law applicable to property rights in the context of an inter-state arbitration based on a treaty. While the majority applied international private law principles to determine the domestic law applicable to questions of ownership, several of the dissenting arbitrators expressed the view that the nature of the dispute, as a treaty case, required the exclusive application of public international law. These two diverging approaches offer an interesting perspective on recent investor-state decisions, which also present conflicting views on the role that should be attributed to domestic law in determining the contours of those property rights, which are the subject of treaty violations and the corresponding compensation of investors. property, international law, public international law, private international law, domestic law, applicable law, Iran-US Claims Tribunal, investor-state dispute settlement, investor-state arbitration, choice of law