Leader age, regime type, and violent international relations

In this article, the authors investigate the relationship between states' political leaders' ages, their regime type, and the likelihood of militarized dispute initiation and escalation. They examine more than 100,000 interstate dyads between 1875 and 2002 to systematically test the relationship between leader age and militarized disputes. The results show that, in general, as the age of leaders increases, they become more likely to both initiate and escalate militarized disputes. In addition, the interaction of age and regime type is significant. In personalist regimes, the general effect reverses; as age increases, the relative risk of conflict declines in comparison to other types of regimes. Increasing leader age in democracies increases the relative risk propensity for conflict initiation at a higher level than for personalist regimes, while the impact of increasing leader age is most substantial in intermediate regimes.