Origins and core claims
Jervis (1978) argued that the severity of the security dilemma depends on two variables: whether offense or defense has the advantage, and whether offensive and defensive weapons can be distinguished. If defense has the advantage and weapons are distinguishable, states can provide for their security without threatening others, and cooperation becomes easier. If offense has the advantage, incentives for preemption grow and arms races intensify. Quester (1977) surveyed historical shifts in the balance, and the idea became a core assumption of defensive realism.
The cult of the offensive and the causes of war
Van Evera (1984) and Snyder (1984) argued that a cult of the offensive among European militaries in 1914, the belief that offense was advantaged when machine guns and railways actually favored defense, helped bring about the First World War. Van Evera (1998) generalized the argument, holding that when conquest is believed easy, first-move advantages, windows of opportunity, fait accompli tactics and secrecy intensify and war becomes more likely. Lynn-Jones (1995) reviewed variants of the theory and its critics and defended its usefulness.
Measurement problems and critiques
Glaser and Kaufmann (1998) defined the offense–defense balance as the ratio of the cost of offensive forces to the cost of defensive forces needed to take territory and argued that it can be measured by considering technology, geography and force size. Levy (1984), however, noted the difficulty of classifying weapons as offensive or defensive, and Lieber (2000) argued that in historical cases technology did not shift the balance as predicted. Biddle (2001) held that force employment matters more than technology, and statistical analysis by Gortzak, Haftel and Sweeney (2005) gave the theory only partial support. Glaser (2010) reintegrated it into a rational theory of international politics.
FAQ
- What is offense–defense theory in simple terms?
- If the weapons and terrain of the day favor attackers, countries fear one another more and wars become more frequent; if they favor defenders, the world is more peaceful.
- Can the offense–defense balance really be measured?
- Glaser and Kaufmann proposed a method, but difficulties in classifying weapons and the importance of how forces are used keep its measurability and predictive power under debate.
Sources reviewed: 2026-10-26
References
- Jervis, R. (1978). Cooperation under the security dilemma. World Politics, 30(2), 167–214.
- Quester, G. H. (1977). Offense and Defense in the International System. New York: Wiley.
- Van Evera, S. (1984). The cult of the offensive and the origins of the First World War. International Security, 9(1), 58–107.
- Snyder, J. (1984). The Ideology of the Offensive: Military Decision Making and the Disasters of 1914. Ithaca: Cornell University Press.
- Van Evera, S. (1998). Offense, defense, and the causes of war. International Security, 22(4), 5–43.
- Glaser, C. L., & Kaufmann, C. (1998). What is the offense-defense balance and can we measure it? International Security, 22(4), 44–82.
- Lynn-Jones, S. M. (1995). Offense-defense theory and its critics. Security Studies, 4(4), 660–691.
- Levy, J. S. (1984). The offensive/defensive balance of military technology: A theoretical and historical analysis. International Studies Quarterly, 28(2), 219–238.
- Lieber, K. A. (2000). Grasping the technological peace: The offense-defense balance and international security. International Security, 25(1), 71–104.
- Biddle, S. (2001). Rebuilding the foundations of offense-defense theory. Journal of Politics, 63(3), 741–774.
- Gortzak, Y., Haftel, Y. Z., & Sweeney, K. (2005). Offense-defense theory: An empirical assessment. Journal of Conflict Resolution, 49(1), 67–89.
- Glaser, C. L. (2010). Rational Theory of International Politics. Princeton: Princeton University Press.
- Shimshoni, J. (1990/91). Technology, military advantage, and World War I: A case for military entrepreneurship. International Security, 15(3), 187–215.