E.C. Marchant, Commentary on Thucydides Book 1

4. διαμέλλετε—persist in ... .

5. οἴεσθε κτλ.—you think that peace lasts longest not for those who in using their forces confine themselves to what is right, but (none the less) by their resolution show that, if wronged, they will not put up with it: instead of that, you deal out fair treatment with the object of not annoying others and, where you defend yourselves, of avoiding harm to yourselves. (1) τὸ ἴσον νέμετε represents δίκαια πράσσετε with slight modification: ‘fair treatment to you means (a) not provoking others and (b) overlooking a wrong if you find that self-defence will entail suffering on you.’ (2) ἐπιτρέπειν as practised by Sparta is explained as an attempt μὴ λυπεῖν τε ... βλάπτεσθαι. (All other explanations seem (1) to render ἀμυνόμενοι μὴ β as if it were μὴ ἀ. β, (2) to strain the meaning of τὸ ἴσον νέμετε: νέμω is not ‘control’ here; cf. p. 103 l. 25.

9. ἀλλ᾽ ἐπὶ κτλ.—there is anacoluthon here, since strictly we ought to have ἀλλ̓（ἐκείνοις）οἳ ἂν ... νέμωσι corresponding to οὐ τούτοις κτλ But the ehange greatly heightens the effect.