Document Type : Original Article
Authors
1 Assistant Professor, Faculty of Law, Department of Human Rights and Environmental Law, Shahid Beheshti University, Tehran, Iran.
2 PhD student in International Law, Faculty of Law, Shahid Beheshti University.
Abstract
Contemporary international law exhibits a tendency towards fragmentation, meaning that the general law of state responsibility is divided into treaty-specific subsidiary systems. This article examines the application of the 2001 International Law Commission (ILC) Articles on Responsibility of States for Internationally Wrongful Acts and the formation of a subsidiary system of responsibility in investor-state dispute settlement (ISDS). An examination of arbitral practice reveals that Parts One and Four of the ILC Articles (concerning attribution, breach, circumstances precluding wrongfulness, and general provisions) have been most frequently applied. In contrast, Part Two (content of responsibility, i.e., reparations), although pertaining to state-to-state relations, has often been applied by analogy, and Part Three (implementation of responsibility, i.e., countermeasures) has received less attention. The article also emphasizes the emergence of a subsidiary system of state responsibility within investor-state arbitration. This system, shaped by reliance on Articles 33 and 55 of the ILC Articles, and through the direct conferral of rights to investors, distances itself from traditional rules on the admissibility of claims, such as "the nationality of claims" rule or the "exhaustion of local remedies" requirement—unless explicitly stipulated in the treaty. Arbitral practice has confirmed this distinction, applying the ILC Articles more as a reflection of custom and supplementary rules. Consequently, although investment tribunals have extensively referred to the ILC Articles, such reference has involved modification and adaptation, thus allowing one to speak of the formation of a subsidiary system of responsibility in this field.
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