This study explores the role of the military as an instrument of national power in the transformation of Republics to Empires. It concentrates on two case studies. The first is the Athenian transformation from Radical Democracy to an Informal Empire during the period following the Second Greco-Persian war to the end of the Peloponnesian War (479-404 B. C.). The second is the Roman Republican Empire's transformation to Formal Empire during the period from the Marian military reforms to the Augustan Principate (107-27 B. C.). The central thesis of this study is that the professionalization of a republican military resulting from a transformation required to face an extraordinary threat to the existence of the state, enables expansionist imperial foreign policy when the immediate threat passes. The now fully professional force becomes increasingly dissociated from and exerts an indirect or direct transformative influence upon the parent state. The implication is that the forces that changed republics to empires in classical antiquity operate still yet. There are parallels between the Athenian, Roman, and American experiences. The study concludes that an understanding of macro historical factors is important for the military professional in the service of the United States as it exercises de facto imperial practice. | Military's Role In Enabling Political Transformation by Thomas M Duckworth, Paperback | Indigo Chapters