Abstract
This article introduces a new theory of military innovation, military realism, which argues that senior military leaders spearhead major changes in military doctrine when existing doctrinal mission priorities and theories of victory do not address the most dangerous threats. What I call the military realist perspective drives this doctrinal innovation. Through a case study of change and continuity in US Army doctrine under President Kennedy, this article challenges bureaucratic, military cultural, and civilian realist theories of military innovation. Military realism provides a powerful explanation of a hard case, while the other theories struggle with what should be an easy case.