Using data from the 2011 British Social Attitudes survey (n = 3,311), this article compares British public opinion of the purposes and successes of the Iraq and Afghanistan missions. Public acceptance of military deaths/injuries, the accuracy of public estimates of military fatalities and how these differ according to opinions of the missions are determined. It is found that the British public is doubtful of the missions' achievements and cynical about their purposes. Perceptions of the campaigns were associated with the accuracy of estimations of UK military fatalities, and the acceptability of military deaths/injuries. Implications for social and political theory and British foreign policy are discussed.