I intend to probe the basis of state obligations to support, cooperate, and comply with the International Criminal Court. I ask whether the ICC’s title to coerce (in this case, punish) individuals is in competition with states’ claims to sovereignty (and more particular, the State parties to the Rome Statute). A standard answer is negative, based on the assumption that states have jointly established the ICC by consent, and must now recognize its coercive title. Drawing on recent debates in Kantian political theory (e.g., Flikschuh, Kleingeld, Ripstein), I suggest that the nature of consent in international law is conceptually too weak to support a clear transfer of an authorization to coerce from sovereign states to an international institution like the ICC. Although multilateral treaties like the Rome Statute can perhaps give an international institution legal personality, it is not clear this can involve an assumed and ongoing transfer of coercive authority, particularly when a state decides to exercise its inherent prerogatives. To illustrate this problem I examine the controversial case of the ICC in Uganda. Here the Ugandan state rescinded an earlier request for ICC judicial assistance, and was effectively overruled by the ICC prosecutor. Rather than dissecting the legal debates about the Rome Statute’s permission for such prosecutorial discretion, the paper seeks to determine whether such discretion is conceptually consistent with the underlying assumptions of obligation in international law. While some like Allen Buchanan suggest we can dispense with anachronistic conceptions of state consent in international law, I raise some Kantian reasons against this.