Recent trends in international law scholarship recycle objections to international law advanced by an earlier generation of political and legal realists. Such objections fail to understand the place of international law in the global order. To understand that place, we must distinguish the idea of the rule of law from other understandings of law. That idea is an inherently moral one. Theories of international law that ignore the moral element in law cannot distinguish law as a constraint on power from law as an instrument of power. A Kantian theory of international law can help to recover that moral element.