Investment tribunals rarely examine host state arguments based on international human rights law in great depth. The ICSID award Urbaser v Argentina is the first to provide a detailed discussion of a host state’s human rights counterclaim.  Hence, this decision presents an opportunity to more fully understand the role of human rights in investment arbitration.  As the text of the award is very rich, this post focuses on whether the tribunal has created a precedent for a host state human rights counterclaim in ICSID arbitration...The award in Urbaser v Argentina does create a precedent for a host state human rights counterclaim.  The approach taken by the tribunal makes it easier for counterclaims to fall within a tribunal’s jurisdiction.  However, the substantive law that can form the foundation of the counterclaim, consisting of an ‘obligation to abstain’ is not clearly established based on the texts referred to by the tribunal.  Further, the tribunal’s final reference to this principle is somewhat ambiguous.  Therefore, the next stage in introducing human rights into ICSID arbitration will be to determine, with more precision, which rights are capable of forming the basis of host state human rights counterclaim.