Should I Stay or Should I Go Now? Partisanship, Approval, and the Duration of Major Power Democratic Military Interventions

How does the domestic political climate within democratic states affect the duration of their foreign military engagements? To answer this question we combine a rationalist model of war termination with a theory about how partisan politics affects the policy preferences of national leaders to predict the duration of democratic military interventions. Specifically, we examine how changes in a chief executive’s public approval ratings interact with partisanship to affect decisions about the timing of conflict termination. We test our expectations on a set of 47 British, French, and American cases from a new dataset of military interventions by powerful states. Our results suggest that partisanship mediates the effect of public approval on the duration of military operations initiated by powerful democratic countries. As executive approval declines, governments on the right of the political spectrum are inclined to continue to fight, while left-leaning executives become more likely to bring the troops home.