It is widely acknowledged that human rights law and international criminal law share core normative features. Yet, the literature has not yet reconstructed this underlying basis in a systematic way. In this contribution, I lay down the basis of such an account. I first identify a similar tension between a “moral” and a “political” approach to the normative foundations of those norms and to the legitimate role of international courts and tribunals adjudicating those norms. With a view to bring the (...) debate forward, I then turn to the practices of HRL and international criminal law to examine which of those approaches best illuminates some salient aspects of the adjudication of ICs. Finally, I argue that the political approach best explains the practice. While each preserves a distinct role, HRL and ICL both establish the basic conditions for the primary subject of international law, namely the state, to legitimately govern its own subjects constructed as free and equal moral agents. (shrink)