Defensive neorealism is a structural theory derived from the school of
realism in
International Relations theory. It finds its foundation in
Kenneth Waltz’s
Theory of International Politics, in which Waltz argues that the anarchical structure of the international system encourages states to maintain moderate and reserved policies to attain security. In contrast,
offensive realism assumes that states seek to maximize their power and influence to achieve security through domination and hegemony. Defensive neorealism asserts that aggressive expansion as promoted by offensive neorealists upsets the tendency of states to conform to the
balance of power theory, thereby decreasing the primary objective of the state, which they argue is ensuring its security. While defensive realism does not deny the reality of interstate conflict, nor that incentives for state expansion do not exist, it contends that these incentives are sporadic rather than endemic. Defensive neorealism points towards “structural modifiers” such as the
security dilemma and geography, and elite beliefs and perceptions to explain the outbreak of conflict.