In the law of peoples Rawls is concerned with the justice and peaceful coexistence of well-ordered societies as members of a society of peoples. Well-ordered peoples, importantly, have institutions of self-government or of consultation in their internal governance. For Rawls, well-ordered peoples include reasonable liberal peoples and decent peoples, which, although they are not liberal, are not aggressive, recognize human rights, and have a legitimate political and legal order. A key part of this project is to argue for the principles which well-ordered peoples can agree on to guide their conduct in the international domain. Rawls argues that the Law of Peoples he endorses is a realistic utopia. It is realistic because it takes account of many real conditions, such as the fact that not all peoples of the world do or can reasonably be made to endorse liberal principles. The eight core principles that constitute the Law of Peoples can, by contrast, be endorsed by all well-ordered peoples, or at least they have no reason to reject them.

Rawls’s argument occurs in several stages. First, he concerns himself only with liberal peoples and the principles they would have reason to endorse. He employs a second original position to derive his Law of Peoples for liberal peoples. In the first original position, the parties select principles to regulate the basic structure of society. After the principles governing domestic society have been derived, Rawls moves to the international level. At this stage, the second original position is employed to derive the foreign policy that liberal peoples would choose. The representatives of peoples are subject to an appropriate veil of ignorance for the situation. For instance, they do not know the size of the territory or population, its relative strength, or its level of economic development.