International law has one principal mechanism for settling the legality of humanitarian interventions, the United Nations Security Council's power to authorise coercion. However, this is hardly satisfactory in practice and has failed to provide a more secure juridical basis for determining significant conflicts among states over when humanitarian force is justified. This article argues that, in spite of Immanuel Kant's limited analysis of intervention, and his silence on humanitarian intervention, his political theory provides the elements of a compelling analysis on (...) this topic. Five components of Kant's roadmap towards perpetual peace and an eventual world republic give conditional support for humanitarian intervention even in imperfect juridical conditions. This support is conditional on the achievement of juridical progress within and among states and has implications for the development of cosmopolitan citizenship. From Kant we learn that, ultimately, humanitarian intervention should become a matter of coercive law enforcement rather than an ethical question of ‘saving strangers’. (shrink)