In this interpretation, the late Republic had temporarily run out of external threats proportionate to its military system. Rome's neighbors had not yet grown strong enough to restore an external balance. Armies and commanders still sought conquest and prestige, but their most rewarding target had become Rome. Caesar accelerated that shift, though earlier civil conflicts had already pointed in the same direction.
Notable Point · 5:43-7:07
Roman expansion turns conquest inward
Rome's success against external rivals left oversized armies and glory-seeking commanders to compete for control of Rome itself.