The general issue addressed in this paper is the relation between the rule of law as a matter of national law, and as a matter of international law. Different institutional conceptions of this relationship give rise to different attitudes towards international law. Nonetheless, questions arise that cast doubt on age-old tenets of certain Western countries concerning the radical separability between the rule of law within the domestic system and in the international realm. The article will start considering some recent developments in the United States' treatment of alien detainees. Then it shall address the relation between domestic constitutions and international legal systems, pointing out the challenge coming from the development of super partes international law and jus cogens. The question concerning the appeal to the rule of law will be made: Can our attitude to the rule of international law be exempted from consistency with the rule of law that we claim for our domestic system? In order to answer this question (in the negative), an appropriate theoretical perspective is eventually proposed and displayed.