of political thought
, often known as Realpolitik
, which deals with international relations
. Realism was very popular in the U.S.
during the cold war
. The person most often credit
ed with the invention of realism as we know it today is Hans Morgenthau
Realism treats the state as the primary unit of analysis. States are presumed to act coherently and rationally---that is, in their own best interests. The arena of international relations is assumed in Realpolitik to be anarchical: states have only other states to answer to for their actions. According to realism, the driving force behind international politics is power---the ability to cause another actor to act for one's own, instead of its, best interest. Power comes in many forms: military, economic, technological, etc.
Realism is seen by many as an extension of Ayn Rand's objectivism into the sphere of international politics.