Who defines International politics like all politics is a struggle for power?

The idea that "all politics is a struggle for power" is often associated with the realist school of thought in international relations, particularly articulated by theorists like Hans Morgenthau. Realism posits that states act primarily in their self-interest, seeking to maximize their power and security in an anarchic international system. This perspective emphasizes the competitive and conflictual nature of international interactions, viewing power as the central currency of political relations among states.