Don’t Look Back in Anger: Cooperation Despite Conflicting Historical Narratives

States in conflict often have divergent interpretations of the past. They blame each other for starting the conflict and view their own actions as justified retaliation, which makes them reluctant to cooperate. This phenomenon, while common in international relations, is not well understood by existing formal theories of cooperation. In the context of the Repeated Prisoner’s Dilemma framework, we show that strategies that demand atonement for past misdeeds are outperformed by strategies that do not. The latter are able to get out of retaliatory cycles and return to cooperation more quickly when there are divergent perceptions of the past. We conclude with a case study of Chinese and U.S. responses to the Tiananmen protests of 1989. China and the United States strongly disagree about the cause of the Tiananmen uprising and the legitimacy of the Chinese response, but nevertheless returned to cooperation after a limited period of mutual punishment.