Citizenship and Service: From Roman Auxiliaries to U.S. Military Naturalization Programs

This article compares ancient Rome and the United States to show that military service has not always been a way for everyone to become a citizen. In Rome, non-citizen auxiliary soldiers were integrated via a standardised legal agreement that conferred citizenship upon honourable discharge, formalised by the diploma militaris. This predictable system met the needs of the population and made it easier for provinces to slowly come together. The United States created a more flexible and episodic system in which military service by immigrants has sometimes sped up the process of becoming a citizen, from the Revolutionary War to the time after 9/11, often because there were not enough soldiers. The American system has been legally broken up and made harder to work with by immigration policy and the all-volunteer force, unlike Rome’s institutionalised approach. The article demonstrates that military service fosters integration most effectively when it is consistently transformed into legal recognition, emphasising the integrative efficacy of standardisation in Rome and the precariousness of service-based inclusion in the United States, all within the context of broader theories of empire, citizenship, and state capacity.