Did the Roman Republic fall through militarization while the Empire fell through loss of a unified military?
Short answerMilitarization mattered, but political instability and a franchise that failed to grow with Rome's territory and armies were more important.
NotesMilitarization mattered, but the deeper problem was the Republic's declining ability to balance factions and produce stability. Earlier commanders such as Sulla or Scipio Africanus did not command the same political coalition that Julius Caesar later assembled. Territorial and military expansion outpaced the franchise and the institutions through which subjects could influence the state. That mismatch created demand for a central organizing authority, helping an emperor become the figure around whom the enlarged system could be stabilized.