As the fourth century BC came around, most Greek men of fighting age would have had a taste of the long Peloponnesian War (431-404). For a few decades, the whole Greek leadership would be composed of men who fought in this conflict and had their worldviews shaped by it. Outside of Greece and especially in the upstart state of Rome, the tactics and practices of the conflict would be studied as examples of ‘modern’ warfare: large battles, the dominance of the phalanx, the imperative of drill and discipline, the commitment of monstrous resources by the state to war and the very real possibility that a defeated city would be razed, its civilian population (that is, women children and elderly men) would be slaughtered or enslaved. The Romans actually let go of the phalanx for the cohort and the short spear, but the ruthlessness was certainly there.
At this point, the Greek world had known this particular style of warfare for a little more than a century – the 14-year Persian War that ended in 478 BC left a few razed cities in its wake. But the Peloponnesian War wasn’t your grandfather’s war – this time Greek cities were pitted against each other on a grand scale. There had been plenty of Greek mercenaries fighting for the Persians before, but this was different. Pericles’ famous exhortation to his troops – we will win because free men have a stronger will to fight in a just war – didn’t make sense in a war pitting free men against each other.
The Greeks of the time had to know that the nature of war had changed. It probably reinforced their belief that they were living in an era where men were inferior to their much-celebrated ancestors.
The Romans seemed to draw a different conclusion: the ruthless will inherit the future.