Objective/context: This article introduces debates on Nancy Cartwright’s concept of nomological machines applied to international relations theory. What the neo-neo synthesis claims as the essence of the international system is a set of conditions imposed upon international phenomena for the latter to fit into the theories themselves. It argues that the law-like explanations tailored by neorealism and neoliberalism are by no means a representation of the world as it is, but rather a predication of the world as these theories want it to be. Methodology: It critically reviews the foundations of neo-neo theories, suggesting a philosophical methodology by reframing the ontological terms of neorealism and neoliberalism based on the concept of nomological machines. Conclusions: This article contends that neo-neo theories could benefit from a capacities-oriented approach, which offers a less categorical understanding of how explanations of international phenomena are tailored, allowing alternative principles to provide invaluable insights about the international system. Originality: This paper innovates by intersecting the ideas of nomological machines with the metatheoretical debate on international relations, thus enabling theoretical improvement.