Conclusion

Abstract

In early modern international society, Natural Law stood in for what we now call jus cogens. Its prohibitions were not only categorical, but also justified and perhaps even mandated a wide right of enforcement in the form of international punishment. Growing political dissatisfaction with the practice of international punishment and parallel philosophical dissatisfaction with its predicate basis in Natural Law led to the supplanting of these peremptory norms with new ones: absolute sovereignty, sovereign equality, and nonintervention. When in the mid-twentieth century these norms were presented as shields behind which to perpetrate genocides, this led to the displacement of these norms as peremptory by new norms. These new norms prohibit unconditionally acts that were considered the sovereign prerogatives of states in the previous era; these proscribed acts—it is now claimed—generate a universal right (and perhaps universal obligation) to prevent and punish their commission. They are prohibited at all times and under all circumstances, and are thus jus cogens. We also have a subsidiary category of norms that plays a similar role, obligations erga omnes.