Political groups, leader change, and the pattern of international cooperation

Nations are politically heterogeneous and which group is in political ascendency shapes the nature of interstate cooperation through two mechanisms. First, groups differ in the benefits they receive from cooperation. This affects which groups can commit to cooperate. Second, a nation may selectively withhold cooperation from one group to influence the domestic political competition between groups in another nation. By integrating political competition between leaders of different groups under different institutional rules into a prisoner's dilemma model of international cooperation, the theory generates hypotheses relating leader turnover, group membership, and patterns of cooperation.