Offense-Defense Balance, War Duration, and the Security Dilemma

The systemic offense–defense theory argues that the security dilemma and the risk of war become doubly severe in offense-dominant eras in the state system. However, the theory assumes in support of its main argument that wars are shorter when offense has the advantage. This article empirically tests the expected connec-tion between the systemic offense–defense balance and war duration. A statistical analysis of wars 1817–1992 disconfirms the theory’s expectations. The article then draws different conclusions about the severity of the security dilemma when offense is dominant: both arms racing and the fear of aggression that the security dilemma thrives on should be less severe than offense–defense theorists assume. Keywords war duration, offense-defense balance, security dilemma Why are some wars longer than others? And how does the expected length of wars influence the security dilemma? The subject of the duration of wars has not received as wide coverage as the study of the causes of war, as scholars perhaps fear that they might confer legitimacy on limited wars (Fox 1970). However, understanding the causes of war duration should not be less important considering the often high cost