Rigor Mortis or Rigor, More Tests: Necessity, Sufficiency, and Deterrence Logic

The critique of rational deterrence constitutes one of the most comprehensive and sustained attacks on a “theory” in the field of international relations, a theory that many still believe is a sound, parsimonious, policy‐relevant explanation of both human‐social and military‐strategic behavior. The attempt to identify the theoretical problems that plague the theory's behavioral assumptions, 1 the methodological errors embedded within a great deal of deterrence literature, 2 and the practical problems associated with implementing deterrence as a strategy 3 encompass the main thrusts of the critique. As Fischoff (1987:73) claims in his summary of the findings from this body of work, “deterrence emerges as a shabby parody of a scientific theory. Its fundamental behavioral assumptions are wrong. Its basic terms are ill‐defined. It is used in inconsistent and contradictory ways. Commonly cited examples of effective deterrence are often based on flawed readings of history, sometimes reflecting ignorance, sometimes deliberate misrepresentation.” Like Fischoff, many remain convinced that these findings provide more than enough evidence to discard deterrence as a weak, if not irrelevant, theory of crisis management behavior. In this article I highlight several fundamental problems with the logic and evidence cited by critics to draw these conclusions. The argument develops in five stages. The first outlines the elements of the main “necessary” condition hypothesis most frequently cited, tested, and rejected by critics of deterrence theory. The second section describes nine additional deterrence hypotheses derived from the logic of necessity and sufficiency, and specifies the relationship between these core hypotheses and the empirical evidence required to support and/or refute them. The third introduces the methodology used to test each hypothesis. It is followed by the fourth stage: discussion of data and findings. I conclude my argument with a few observations about the status and future of deterrence theory and testing.