§5.29.1Μαντινῆς δ’ αὐτοῖς καὶ οἱ ξύμμαχοι αὐτῶν πρῶτοι προσεχώρησαν, δεδιότες τοὺς Λακεδαιμονίους.
The Mantineans and their allies were the first to join them, out of fear of the Lacedaemonians.
τοῖς γὰρ Μαντινεῦσι μέρος τι τῆς Ἀρκαδίας κατέστραπτο ὑπήκοον ἔτι τοῦ πρὸς Ἀθηναίους πολέμου ὄντος, καὶ ἐνόμιζον οὐ περιόψεσθαι σφᾶς τοὺς Λακεδαιμονίους ἄρχειν, ἐπειδὴ καὶ σχολὴν ἦγον·
For a certain part of Arcadia had been brought into subjection by the Mantineans while the war against the Athenians was still going on, and they thought that the Lacedaemonians would not allow them to keep their rule, now that they were at leisure.
ὥστε ἄσμενοι πρὸς τοὺς Ἀργείους ἐτράποντο, πόλιν τε μεγάλην νομίζοντες καὶ Λακεδαιμονίοις αἰεὶ διάφορον, δημοκρατουμένην τε ὥσπερ καὶ αὐτοί.
Therefore, they gladly turned to the Argives, regarding them as a great city, always at variance with the Lacedaemonians, and democratically governed like themselves.
§5.29.2ἀποστάντων δὲ τῶν Μαντινέων καὶ ἡ ἄλλη Πελοπόννησος ἐς θροῦν καθίστατο ὡς καὶ σφίσι ποιητέον τοῦτο, νομίσαντες πλέον τέ τι εἰδότας μεταστῆναι αὐτοὺς καὶ τοὺς Λακεδαιμονίους ἅμα δι’ ὀργῆς ἔχοντες, ἐν ἄλλοις τε καὶ ὅτι ἐν ταῖς σπονδαῖς ταῖς Ἀττικαῖς ἐγέγραπτο εὔορκον εἶναι προσθεῖναι καὶ ἀφελεῖν ὅτι ἂν ἀμφοῖν τοῖν πολέοιν δοκῇ, Λακεδαιμονίοις καὶ Ἀθηναίοις.
When the Mantineans revolted, the rest of the Peloponnese also fell into a state of murmuring that they too must do this, thinking that the Mantineans had changed sides because they knew something more, and at the same time being angry with the Lacedaemonians, among other reasons because it had been written in the Attic treaty that it should be consistent with their oath to add or take away whatever might seem good to both cities, the Lacedaemonians and the Athenians.
§5.29.3τοῦτο γὰρ τὸ γράμμα μάλιστα τὴν Πελοπόννησον διεθορύβει καὶ ἐς ὑποψίαν καθίστη μὴ μετὰ Ἀθηναίων σφᾶς βούλωνται Λακεδαιμόνιοι δουλώσασθαι· δίκαιον γὰρ εἶναι πᾶσι τοῖς ξυμμάχοις γεγράφθαι τὴν μετάθεσιν.
For this clause especially disturbed the Peloponnese and brought them into suspicion that the Lacedaemonians, in concert with the Athenians, wished to enslave them; for they thought it was just that any alteration should be written for all the allies.
§5.29.4ὥστε φοβούμενοι οἱ πολλοὶ ὥρμηντο πρὸς τοὺς Ἀργείους καὶ αὐτοὶ ἕκαστοι ξυμμαχίαν ποιεῖσθαι.
So, out of fear, the majority were eager, each for themselves, to make an alliance with the Argives.