This article applies a three-dimensional framework for the analysis of the role of motivation in foreign policy decision-making to the foreign policy decisions of individuals and cities in Thucydides' History of the Peloponnesian War. First, the authors briefly introduce their framework for analysis. Using the speeches in Thucydides to explicate the motives and goals of individuals and cities, the authors then trace the relationships between the motivational dispositions of foreign policy actors and their foreign policy behaviour. In so doing, they demonstrate both the relevance of a concern with individual motivation for foreign policy analysis and the usefulness of their analytical framework for studying the impact of the relevant motives. The authors also show how ideological statements can be analysed to determine the relative salience of individual motives and collective goals, suggesting a relationship between ideological reasoning and motivational imbalance which can adversely affect the policymaking process. In conclusion, they briefly assess the theoretical and normative as well as practical policy implications of their observations.