Recently, environmental and human rights (EHR) counterclaims in investment arbitration have attracted much attention as a vehicle to recalibrate the investor–state relationship. However, until now, successful instances of EHR counterclaims have been admittedly rare. As explained in this paper, some of the major barriers to EHR counterclaims in investment arbitration, and some of the concerns associated with them, are rooted in the domestic law basis of such counterclaims. Contrary to the position of several commentators, this paper argues that the grounding of EHR counterclaims on international law is neither practical nor beneficial, and EHR counterclaims are necessarily based on domestic law. Therefore, when investment arbitral tribunals adjudicate EHR counterclaims, they essentially act as an alternative to domestic courts. This has several implications. First, on questions of jurisdiction and admissibility of EHR counterclaims, decisions of states and arbitral tribunals essentially turn on the pros and cons of having these claims adjudicated by investment arbitral tribunals as opposed to domestic courts. Second, weaknesses in domestic rules, including the difficulty of holding shareholders accountable, would carry over to EHR counterclaims. Such problems can only be efficiently tackled at the level of domestic law. Third, as revealed from the inconsistent decisions in Perenco and Burlington on the merits of the environmental counterclaims, having investment arbitral tribunals adjudicate domestic law-based EHR counterclaims may cause certain concerns. For EHR counterclaims to play a more beneficial role, decision-makers must bear in mind these factors and concerns when taking their policy choices.

中文翻译：

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国际投资仲裁中的环境和人权反诉：在国内法和国际法的十字路口

最近，投资仲裁中的环境与人权 (EHR) 反诉作为重新调整投资者与国家关系的工具而备受关注。然而，直到现在，成功的 EHR 反诉案例确实很少见。正如本文所解释的，投资仲裁中 EHR 反诉的一些主要障碍，以及与之相关的一些担忧，都植根于此类反诉的国内法基础。与几位评论者的立场相反，本文认为 EHR 反诉以国际法为依据既不实用也无益，而 EHR 反诉必然基于国内法。因此，当投资仲裁庭对 EHR 反诉进行裁决时，它们实质上是国内法院的替代方案。这有几个含义。首先，关于 EHR 反诉的管辖权和可受理性问题，国家和仲裁庭的决定基本上取决于投资仲裁庭而非国内法院裁决这些诉求的利弊。其次，国内规则的弱点，包括难以追究股东责任，将延续到 EHR 反诉。这些问题只能在国内法层面得到有效解决。第三，正如 Perenco 和 Burlington 对环境反诉案情的不一致裁决所揭示的那样，让投资仲裁庭裁决基于国内法律的 EHR 反诉可能会引起某些担忧。为了让 EHR 反诉发挥更有益的作用，