Leadership and Military Effectiveness

What determines military effectiveness? Though political scientists have studied the sources of military effectiveness, they have generally ignored the role of military leadership, a factor that historians have emphasized as crucial for effectiveness. This article presents the first rigorous examination of the proposition that militaries improve effectiveness by replacing low-performing leaders. The article tests three theories describing how militaries promote and demote leaders: (1) military leaders are promoted and demoted on the basis of combat performance; (2) political leaders fearful of coups do not demote low-performing military leaders, as a coup-proofing tactic; and (3) military leaders that belong to powerful interpersonal networks are less likely to be demoted and more likely to be promoted. Hypotheses are tested using new data on all American and German generals holding combat commands in the North African, Italian, and West European theaters in World War II and new data on the monthly combat performance of American and German divisions in these theaters. Analysis reveals that both armies replaced low-performing generals (coup-proofing motives did not prevent Hitler from demoting low performers) and that interpersonal networks in the US army did not block demotion of low performers. Also, the replacement of low-performing generals improved combat effectiveness in both armies.