Introduction: Roughly six decades have passed since the emergence of neorealism/structural realism in International Relations. Throughout this period, scientifically oriented neorealists have intervened prescriptively in debates on foreign policy. Since some critics of neorealism consider its prescriptive implications to be inconsistent with its scientific and/or structuralist character and given that no comprehensive and independent discussion has yet been presented in response to this critique, this article seeks to demonstrate that such criticisms are not justified based on neorealism’s metatheoretical foundations. In response to the question of how neorealism’s metatheoretical premises justify these prescriptions, the article seeks to demonstrate that, based on the philosophy of social science, neorealism’s prescriptivism is consistent with its scientific structuralist approach.

Method: Text analysis was applied to texts on philosophy of social science (to elucidate the metatheoretical underpinnings of prescriptivism) and to neorealist relevant texts (to demonstrate how neorealists arrive from a structural theory to policy prescriptions).

Findings: Based on authoritative texts in the philosophy of social science, there is no inherent incompatibility between science and structuralism, on the one hand, and prescriptivism, on the other. Analysis of the writings of prominent neorealists also shows how they move from scientistic and structuralist foundations to specific foreign-policy prescriptions, grounded in the assumption of actor rationality. Even Waltz, despite emphasizing that his structural theory does not require the assumption of actor rationality, has in practice presumed a form of constructed rationality based on socialization—a point that constitutes one of this article’s innovations. Van Evera explicitly regards prescription as a necessary component of scientific inquiry and specifies the conditions under which it is useful. Misunderstandings that lead to misguided policies and failure stem from the limitations of state learning, and this very fact justifies the prescriptive dimension of IR theory. His own prescriptive writings reflect theoretical flexibility and a multidimensional perspective. Walt has repeatedly emphasized the importance of realist prescriptions for foreign policy. He has engaged extensively in foreign-policy debates/prescriptions and addressed the misperceptions and misunderstandings of American policymakers. Mearsheimer, who seeks to bridge the gap between realist theoretical discussions and the foreign policy of great powers, warns against dysfunctions and errors in U.S. foreign policy. He explicitly equates rational foreign policy with good foreign policy, which in turn requires him to critique irrationality in policy-makings. He draws policymakers’ attention to the “realities” that realism articulates about international politics in order to modify their behavior.

What unites the neorealists examined in this article, beyond the prescriptive approach evident in much of their work, is prudence or “restraint” as a fundamental element. When Waltz speaks of the proper amount of power, or when Mearsheimer and Walt stress the need to avoid unnecessary conflicts, they reflect a long-standing realist tradition that regards caution and consideration of others’ interests and reactions as essential.

Conclusion: Based on texts in the philosophy of social science and the views of the realists themselves, there is no conflict between scientific approach and structuralism, on the one hand, and offering prescriptions, on the other. Neorealists, by assuming a form of rationality, arrive at the role of agency and criticize behaviors that diverge from rationality. At the same time, this rationalist outlook is not confined to cost-benefit rationality but also encompasses prudence.