This chapter seeks to grapple with the puzzle of placing the various figurations of the UN within the main strands of international ethics. It starts out by introducing the positions of realism, internationalism and cosmopolitanism. Then, these are related to four dimensions of the UN: the Charter, the actors of the organisation, the domains of operation, and its political functions. It is demonstrated that all four dimensions reflect the combination in the Charter of an internationalist legal framework and a cosmopolitan agenda of serving the rights of individuals through international collaboration. With sufficient political consensus in the Security Council, this combination results in the ethical position of internationalist solidarism, advancing a qualified version of internationalism on cosmopolitan grounds. Yet, the reliance of the UN on the active support of states means that it is continuously resting on political compromises between this cosmopolitan presumption and the self-interest of major powers, entailing a more pluralist kind of internationalism. The ethical character of the UN is thereby rendered as variations on a gradual scale of internationalism, bordering realism on the one side and cosmopolitanism on the other.