Roman (non-)combatants / insurgents

[Paullus Scipio]

the Romans waged war against communities, not against "armies".

Indeed, Duncan. Whole cities were sometimes put to the sword, all their tangible goods taken away, and the buildings and walls razed to the ground. Sometimes that was just to make an example to the neighbors that this would be the fate of all who opposed Rome. Unless there was some other political motive to bring the Senate to try the general, I don't recall reading much negative being said to them, or accounts of their having been brought to the floor to answer for their conduct. Usually, the conquering general was given honors and rewards, and a Senatorial attaboy.

Quite right, M. Demetrius !! Until 'professional' full time armies came along in Greek and Roman times, all wars were between 'communities', a.k.a "the people in arms" - from which principle the U.S.A's founding fathers established the right of every citizen to bear arms, for good or ill, envisioning, as with those ancient communities, the whole people defending themselves. The armies of early Rome and the Middle Republic were just such armies.

As I remarked in the 'Latinatas questions for his school report' thread, Terrorism/frightfulness was a weapon of policy in ancient cultures, and the Romans among the foremost practitioners - there was no division of 'the enemy' into civilians' and 'soldiers'.

Any enemy not put to the 'fire and sword' were the prize booty ( clay pots and pitiful implements, the vast content of most homes were worth little or nothing, but 'enemy'humans were worth a fortune sold into slavery, and usually formed the most valuable part of any booty).

One aspect of the 'frightfulness' of massacring thousands not readily appreciated is that it demonstrated the Romans were prepared to forego a fortune in valuable slaves, in order to 'teach a lesson' to the enemy, and any potential enemy.

The Romans were sticklers too for observing the proprieties or legalities of war-making, going to lengths to ensure a 'just cause' ( in order to ensure the favour of the Gods in such a life-and-death matter) including the age-old custom of hurling a spear into enemy territory, and as you point out, a failure to make a war 'legal' could, on rare occasions, result in a Commander being prosecuted by his political enemies ( J. Caesar was accused of making illegal war in Gaul, IIRC).....though a successful commander, as you say, could be forgiven much !!