Offense, Defense, and War

  • Published

Offense, Defense, and War edited by Michael Brown, Owen Cote, Sean Lynn-Jones, and Steven Miller. MIT Press, 2005, 444 pp.

Offense, Defense, and War presents a compilation of seminal articles on offense-defense theory spanning nearly 30 years. Little changed from earlier iterations of the same title, it seeks to communicate offense-defense as a robust and reliable theory of predicting the outcome of wars predicated upon analysis rooted in game theory. It provides a summary of the key elements of the theory as well as arguments against it and a commendable list of additional readings. Though it does not dispel all challenges posed by critics, it is honest in its handling of dissenting views, thereby showcasing the debate for those interested in the lengthy discourse this theory has engendered.

Proponents include Robert Jervis, Stephen Van Evera, George Quester and others. Perhaps the most cited article in the literature, Jervis’ “Cooperation under the Security Dilemma,” leads the presentation. He argues a realist viewpoint that the international security dilemma posed by an anarchic world system leads states to attack others to gain power and thereby protect their interests. However, states with little perceived vulnerability might pursue more-defensive strategies, thereby increasing the relative security of states that would otherwise be threatened. From this, he deduces the central question: Is a state more focused on defense or offense? By determining which approach (offense or defense) has the greater utility in a given situation—with geography and technology as key factors—and confirming a state’s intentions by assessing its weaponry (offensive versus defensive) to determine what type of war it is prepared to fight, analysts can determine the relative threat one state poses to others.

Given this, the world faces four potential outcomes. (1) War becomes more likely when offense has the advantage and the type of weapons held by a state cannot be differentiated. (2) However, when defense has the advantage and weapons cannot be differentiated, uncertainty increases within the security environment driving most states to develop compatible security policies that minimize war. (3) When the offense has the advantage and weapons can be differentiated, states come to a crossroads where negotiations may provide stability, but states may also act upon the increased certainty of threats to secure their position through aggression. (4) Finally, the safest condition exists when the defense has the advantage and weapons can be differentiated. Van Evera and others further extended and deepened these concepts.

In the final chapters of the book, Richard Betts and other critics take issue with the theory. They begin by attacking the “gross megavariable” that arises from the conflating the offense-defense components. Not only does this variable prove unwieldy, but it fails to account for the relative strength and key interests of states. A failure to use well-defined terms and methodology also takes well-deserved barbs. For example, as Kier Lieber notes, the assessment of weapon use (offensive versus defensive) remains subjective and inaccurate. The critics also take umbrage at the overreliance on World War I as an exemplar while maintaining an agnosticism toward the peace engendered by nuclear deterrence throughout the Cold War or conflict between smaller nations or nonstate actors.

Karen Adams’ work concludes the book with a quantitative analysis of key claims of the theory. She finds variance in the reliability of the theory according to the type of states involved. The great power conflicts showed reasonable reliability conflicts with lesser states did not. Reliability also diminished over time unless additional work was done to account for changing lethality, protection, and deterrence that arises from new technology and military operations. She offers an alternative solution with better accounting in a three-pronged model emphasizing offense, defense, and deterrence.

Although a laudable compendium of thoughts for and against the offense-defense theory, a number of notable works are missing to include critics like Stephen Biddle, Colin Gray, Samuel Huntington, and James Fearon. Also absent are supporting authors who have tried to extend the work to account for conflict driven by nonstate forces such as ethnic conflict and revolutions, such as William Rose and Stephen Walt. The failure to add such pieces bolsters the critics’ points that the theory fails to show validity across the spectrum of conflict. To the editors’ credit, they place many of these and other works in the suggested reading section.

The pervasive influence of the offense-defense theory in international relations presents sufficient reason for one to engage this text. However, it is not a simple primer. It does nothing to develop common terminology or standards to aid future studies. Commendably, this work is not clogged with the statistical analysis common to this discussion, though it does have some quantitative work that requires grounding in statistics.

In summary, this book provides a good basis for understanding the nature of the offense-defense debate. However, it does not present any new work beyond some suggestions for further development. Researchers may benefit from this book, but policymakers and practitioners will likely find it cumbersome, though it could help fit them for battle against those who argue the existence of Jominian “optimal military postures” based on this theory’s tenets.

Lt Col Brett Morris, PhD, USAF

Professor, Air Command and Staff College

"The views expressed are those of the author(s) and do not reflect the official policy or position of the US government or the Department of Defense."