The name of Thomas Hobbes and the tradition of Realism have become virtually synonymous in discussions within International Relations. Indeed the claim that international politics is best described as an anarchic ‘Hobbesian state of nature’ continues to be one of the prominent and evocative common rhetorical devices and analytic touchstones in the study of world politics, much as it has in varying forms for generations. As Michael J. Smith puts it, Hobbes' ‘analysis of the state of nature remains the defining feature of realist thought. His notion of the international state of nature as a state of war is shared by virtually everyone calling himself a realist’; while in the words of Hans Morgenthau, it provides the ‘stock in trade’ of the discipline of International Relations.

The attractions of Hobbes' thinking for a Realist theory of International Relations are easy enough to see. His stress on the human capacity for mendacity, treachery, and violence seems to accord nicely with long-standing Realist concerns with the ‘darker’ side of human nature. Alternatively, for contemporary theorists more suspicious of appeals to evil or human nature, Hobbes can also seem to have captured in a particularly graphic form the dynamics of rational action under a condition of anarchy, and to provide a classic account of the difficulties of cooperation and coordination in the absence of an overarching authority with an ability to enforce rules and ensure compliance.