The UN and its Charter, despite the many laudable aims, legal principles and values it enshrines, is today too heavily constrained by the commitments it makes to uphold outdated notions of state sovereignty; it is saddled by the veto; it is inadequately resourced; it has not succeeded in establishing a genuine international system of rule by law; and it has consistently proved incapable of controlling or preventing abuses of power and other forms of internationally dangerous state behavior. Nevertheless, we argue that the more sensible approach in developing the foundations of an enhanced global constitutional order is to build on the existing institutional infrastructure associated with the United Nations: it has universal membership; it has accumulated over the past 70 years a body of texts and practices that have precipitated important changes in selected areas; it has participated, however ineffectively, in most of the peace and security debates of the postwar period; and the Security Council has the power to enforce binding international law. More importantly, the UN Charter can be amended, modernized and adapted to the needs of the present. We discuss the possible ways ahead, suggesting the most workable mechanisms for next steps in our evolving governance system.