[1] In contrast, offensive realism assumes that states seek to maximize their power and influence to achieve security through domination and hegemony.
Defensive neorealism points towards "structural modifiers," such as the security dilemma and geography, and elite beliefs and perceptions to explain the outbreak of conflict.
Neorealism therefore works from realism's five base theoretical assumptions as outlined by offensive neorealist scholar John J. Mearsheimer in "The False Promise of International Institutions".
[6] However, neorealism departs from classical realism's other main assumption that it is the flaws and complexities of human nature that drive the international system.
This increases the already expensive process of occupation, especially in societies that rely on freedom of movement and transportation for economic prosperity because these are vulnerable to sabotage and embargo.
In addition, newly acquired infrastructure must be protected and rebuilt when destroyed, the defence of new borders must be consolidated, and the possible resistance of local workers to contributing skilled labour to the new authorities, all combine to place heavy strain on the economic and production capabilities of the conquering state.
They contend that states, especially major powers, can afford to wait for definitive evidence of attack rather than undertaking pre-emptive strikes or reacting inappropriately to inadvertent threats.
[12] The outbreak of World War I and its subsequent hostilities is commonly used as an example in which states erroneously believed offensive capabilities to be superior to those of defense.
[13] A key component of this view is that geography, offensive neorealists such as John Mearsheimer contend, usually inhibits the projection of power due to the natural barriers rivers, mountains, deserts, oceans, jungles, etc., present.
As Stephen Van Evera argues in Causes of War: Power and the Roots of Conflict, sometimes states that wish to maintain the status quo must become the aggressor in order to prevent later aggression against themselves or their allies.
Defensive neorealists however, contend that a favourable offensive balance is the exception rather than the rule, and that unnecessary aggression and expansion is self-defeating and counterproductive.
If the elites realise their mistake, it is incredibly difficult to rectify their grand strategy due to the narrative sold both to its own members and to the general public, effectively condemning the state to defeat.
Despite defensive realism's significant contribution to international relations theory and its number of prominent proponents, such as Kenneth Waltz, Stephen Van Evera, and Charles L. Glaser, it has been criticised both by offensive realists and other scholars.
This can combine with unfavourable structural modifiers such as geography to contradict the idea that states can afford to wait for definitive signs of attack.