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 connection 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.