حسن رجب پوررودمعجنی

In recent years, international investment arbitration has emerged as one of the main tools for resolving disputes between states and foreign investors. In this context, counterclaims brought by host states against foreign investors have been considered as a potential tool for promoting balance in the arbitration process and holding investors accountable for their harmful conduct. This study, with the aim of analyzing and critiquing the work of UNCITRAL Working Group III on counterclaims, examines the legal requirements and practical challenges associated with the initiation of these claims. Therefore, first, the concepts and theoretical foundations related to counterclaims and their position in various legal frameworks, including ICSID and UNCITRAL, are analyzed. Then, relying on arbitration procedures and landmark cases such as the Urbaser v. Argentina case, the current role and limitations of this tool in responding to investor violations are examined. Finally, the performance of UNCITRAL Working Group III in reforming the investment dispute settlement system is criticized from the perspective of balancing interests and justice, and suggestions are made to improve the efficiency of counterclaims. The main goal of this research is to identify and describe the various theoretical and practical obstacles to counterclaims. However, implicitly and in addition to this main goal, the present research should take a serious look at the performance of UNCITRAL Working Group III in order to analyze how this institution operates. Moreover, the present research is bound to examine the performance of UNCITRAL Working Group III and then address the issue of what kind of document is appropriate to cover the ultimate goals of the performance of the Working Group III. The findings of this study show that although counterclaims have significant potential to hold investors liable, limitations such as the lack of recognition of the requirements for the parties' consent to file a counterclaim, the legal connection between the main and counterclaims, and the lack of a clear legal basis still prevent the widespread and effective use of this tool. At the same time, UNCITRAL Working Group III has not yet paid due attention to the importance of this issue. Therefore, reforming investment treaties and developing documents such as model rules and conditions by UNCITRAL can help improve this situation.