Of the causes which commonly give rise to wars between states.
The occasion which led to war between the Romans and Samnites, who for long had been in league with one another, is of common occurrence in all powerful states, being either brought about by accident, or else purposely contrived by someone who would set war afoot. As between the Romans and the Samnites, the occasion of war was accidental. For in making war upon the Sidicinians and afterwards on the Campanians, the Samnites had no thought of involving themselves with the Romans. But the Campanians being overpowered, and, contrary to the expectation of Romans and Samnites alike, resorting to Rome for aid, the Romans, on whose protection they threw themselves, were forced to succour them as dependants, and to accept a war which, it seemed to them, they could not with honour decline. For though they might have thought it unreasonable to be called on to defend the Campanians as friends against their own friends the Samnites, it seemed to them shameful not to defend them as subjects, or as a people who had placed themselves under their protection. For they reasoned that to decline their defence would close the gate against all others who at any future time might desire to submit themselves to their power. And, accordingly, since glory and empire, and not peace, were the ends which they always had in view, it became impossible for them to refuse this protectorship.
A similar circumstance gave rise to the first war with the Carthaginians, namely the protectorate assumed by the Romans of the citizens of Messina in Sicily, and this likewise came about by chance. But the second war with Carthage was not the result of chance. For Hannibal the Carthaginian general attacked the Saguntans, who were the friends of Rome in Spain, not from any desire to injure them, but in order to set the arms of Rome in motion, and so gain an opportunity of engaging the