Fiona McGillivray and Alastair Smith, “The Impact of Leadership Turnover and Domestic Institutions on International Cooperation,” Journal of Conflict Resolution 49 (5) (October 2005), pp. 639-660.
The differences in cooperation between two nations can be attributed to the domestic institutions of those nations if actors within a nation employ leader-specific punishment strategies. The leader of Nation A can punish the leader of Nation B for Nation B's non-cooperative policies by refusing to cooperate with Nation B until the leader is replaced. The citizens of Nation B will lose out on cooperative benefits and have an incentive to remove the non-cooperative leader. Then in cases where leader removal is easy, as in the case of large winning coalition systems such as democracies, leaders will have reduced incentives to defect and states can cooperate deeply. Instances of cooperation breakdown between such nations are rare. In contrast, when one of the nations attempting to reach agreement has a high cost for leader removal, cooperation is shallow. Instances of cheating lead to prolonged periods of non-cooperation.
