As never before, issues with which many lawyers and contemporary political theorists grapple are international in nature. Events, decisions and human challenges that in the past might have been of little consequence or garnered little attention beyond national borders now have much wider repercussions and attract more widespread interest. To reflect these challenges to the convention of international realism, there has been a strong normative shift to cosmopolitan thinking in contemporary political and legal theory. In line with this change, cosmopolitan law has extended the rule of law to the international sphere. The ICC is an innovative form of cosmopolitanism, developing from, and enhancing, Kant’s conception of cosmopolitan law (Kant 1785). This extension of the rule of law, however, produces difficulties for both international and domestic legal systems, demanding complex theoretical discussions concerning their respective roles, responsibilities and aims.