Realism in international relations theory

Realism is an important school of thought in international relations theory, theoretically formalising the realpolitik statesmanship of early modern Europe. Although a highly diverse body of thought, it can be thought of as unified by the belief that world politics ultimately is always and necessarily a field of conflict among actors pursuing power. Crudely, realists are of three kinds in what they take the source of ineliminable conflict to be. Classical realists believe that it follows from human nature, neorealists focus upon the structure of the anarchic state system, and neoclassical realists believe that it is a result of a combination of the two and certain domestic variables. Realists also disagree about what kind of action states ought to take to navigate world politics, dividing between (although most realists fall outside the two groups) defensive realism and offensive realism. Realists have also claimed that a realist tradition of thought is evident within the history of political thought all the way back to antiquity, including Thucydides, Thomas Hobbes and Niccolò Machiavelli.

Jonathan Haslam from the University of Cambridge characterizes Realism as "a spectrum of ideas." Regardless of which definition is used, the theories of realism revolve around four central propositions:

Realism is often associated with Realpolitik as both are based on the management of the pursuit, possession, and application of power. Realpolitik, however, is an older prescriptive guideline limited to policy-making (like foreign policy), while Realism is a particular paradigm, or wider theoretical and methodological framework, aimed at describing, explaining and, eventually, predicting events in the international relations domain. The theories of Realism are contrasted by the cooperative ideals of Liberalism.

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