Realism (international relations)
Realism, in international relations theory, is a theoretical framework that views world politics as an enduring competition among self-interested states vying for power and positioning within an anarchic global system devoid of a centralized authority. It centers on states as rational primary actors navigating a system shaped by power politics, national interest, and a pursuit of security and self-preservation.
Source: Wikipedia — Realism (international relations) (CC BY-SA 4.0)