Thucydides on the Role of Justice in Conflict

‘Ὧν ἐνθυμηθέντες καὶ νεώτερός τις παρὰ πρεσβυτέρου αὐτὰ μαθὼν ἀξιούτω τοῖς ὁμοίοις ἡμᾶς ἀμύνεσθαι, καὶ μὴ νομίσῃ δίκαια μὲν τάδε λέγεσθαι, ξύμφορα δέ, εἰ πολεμήσει, ἄλλα εἶναι. τό τε γὰρ ξυμφέρον ἐν ᾧ ἄν τις ἐλάχιστα ἁμαρτάνῃ μάλιστα ἕπεται, καὶ τὸ μέλλον τοῦ πολέμου ᾧ φοβοῦντες ὑμᾶς Κερκυραῖοι κελεύουσιν ἀδικεῖν ἐν ἀφανεῖ ἔτι κεῖται, καὶ οὐκ ἄξιον ἐπαρθέντας αὐτῷ φανερὰν ἔχθραν ἤδη καὶ οὐ μέλλουσαν πρὸς Κορινθίους κτήσασθαι, τῆς δὲ ὑπαρχούσης πρότερον διὰ Μεγαρέας ὑποψίας σῶφρον ὑφελεῖν μᾶλλον (ἡ γὰρ τελευταία χάρις καιρὸν ἔχουσα, κἂν ἐλάσσων ᾖ, δύναται μεῖζον ἔγκλημα λῦσαι), μηδ’ ὅτι ναυτικοῦ ξυμμαχίαν μεγάλην διδόασι, τούτῳ ἐφέλκεσθαι τὸ γὰρ μὴ ἀδικεῖν τοὺς ὁμοίους ἐχυρωτέρα δύναμις ἢ τῷ αὐτίκα φανερῷ ἐπαρθέντας διὰ κινδύνων τὸ πλέον ἔχειν.

Weigh well these considerations, and let your youth learn what they are from their elders, and let them determine to do unto us as we have done unto you. And let them not acknowledge the justice of what we say, but dispute its wisdom in the contingency of war. Not only is the straightest path generally speaking the wisest; but the coming of the war which the Corcyraeans have used as a bugbear to persuade you to do wrong, is still uncertain, and it is not worth while to be carried away by it into gaining the instant and declared enmity of Corinth. It were, rather, wise to try and counteract the unfavorable impression which your conduct to Megara has created. For kindness opportunely shown has a greater power of removing old grievances than the facts of the case may warrant. And do not be seduced by the prospect of a great naval alliance. Abstinence from all injustice to other first-rate powers is a greater tower of strength, than anything that can be gained by the sacrifice of permanent tranquillity for an apparent temporary advantage.

–Thucydides (Θουκυδίδης), History of the Peloponnesian War, bk i, sec 42 (ca. 411 BCE)