Randall Schweller is a leading neoclassical realist who has paved the way for the revival of realism through criticizing the structuralist approach of neo-realism. Waltz, Walt, and Mearsheimer have been the major targets of his attacks. This article argues that his main added value to realism is to find a way to respond to internal divisions among realists and weak historical support for many of neo-realist propositions. Within this framework he enters into internal debates among realists about status quo versus revisionist states; explains non-formation of balancing behavior and balance of power in the course of history; pays attention to change in international system ignored by many realists; and rejects the objections against realists for not accounting for international institutions. By including domestic factors in his analysis, his work accounts for the emergence of revisionist states, dynamics of international system, and the significance (or insignificance) of international institutions within a theory of states’ interest and the resulting balance of interests in the international system. This theory can clarify the historical conditions in which realists’ claims can prove to be true. In order to give an account of Schweller’s theoretical endeavors to modify and revive realism, this article analyses his major works and shows that although he could account for inconsistences within realism, his own work with its own problems can add to internal divisions within realist camp.