:InThe Law of Peoples, John Rawls introduces a framework for realistic utopia, within which the limits of practicable political possibility are probed through the further development of his international theory. This essay addresses the apparent paradox of realistic utopianism within the context of, and in relation to, ideal theory, in an attempt to explore the scope and limits of Rawls’s theory. The ideas behind Rawls’s realistic utopia are discussed in detail, the concept is contrasted with ideal theory in order to (...) assess to what extent Rawls’s framework for realistic utopia introduced inThe Law of Peoplesdiffers from other forms of ideal theory, and the limits of realistic utopianism are identified.I argue first, that, in an attempt to address the potential feasibility constraint, Rawls tries to distinguish his framework of realistic utopia from that of more traditional ideal theory. I then proceed to examine the differences between realistic utopianism inThe Law of Peoplesand ideal theory inA Theory of Justice. I then conclude that Rawls only partially meets the challenge of establishing practicable political possibility. In actuality, Rawls’s focus on ideal agents in ideal as well as nonideal theory, together with his emphasis on societies as closed and self-sufficient, ignores the potential for noncompliance by liberal and decent societies, as well as interdependencies between societies that can cause or lead to injustice, conflict, and instability. I argue that despite these flaws, Rawls’s approach nevertheless provokes new insights into the function of the principles of the ideal theory framework as guidelines for real-world policies striving toward peace, stability, and justice. (shrink)