Known Knowns and Known Unknowns: Ambiguity Aversion and Foreign Military Intervention

Abstract

Analyses of foreign military intervention have relied heavily upon subjective expected utility theory (SEU) to generate hypotheses and model military decision making. Ambiguity aversion is a robust experimental finding from the cognitive sciences showing that human beings systematically prefer gambles where the probability of winning is known, rather than known with some degree of uncertainty, even when the unknown gamble is technically sub-optimal according to SEU. This paper tests the 'ambiguity aversion' hypotheses against other leading explanations of foreign military intervention. Finding from logit analysis of foreign intervention in civil wars from 1960-2003 suggests that, at least in African civil wars, military decision-makers are uncertainty-minimisers rather than utility maximisers.