History of the Peloponnesian War

In this way you have everything to do with us, and on this account it is perfectly reasonable for us to restore the Leontines, and to make them, not subjects like their kinsmen in Euboea, but as powerful as possible, to help us by annoying the Syracusans from their frontier.

In Hellas we are alone a match for our enemies; and as for the assertion that it is out of all reason that we should free the Sicilian, while we enslave the Chalcidian, the fact is that the latter is useful to us by being without arms and contributing money only; while the former, the Leontines and our other friends, cannot be too independent.

Besides, for tyrants and imperial cities nothing is unreasonable if expedient, no one a kinsman unless sure; but friendship or enmity is everywhere an affair of time and circumstance. Here, in Sicily, our interest is not to weaken our friends, but by means of their strength to cripple our enemies. Why doubt this? In Hellas we treat our allies as we find them useful.