It was that helot revolt which would eventually bring on the crisis that precipitated the war. Unable to quell the revolt themselves, the Spartans summoned all their allies to assist them, invoking the old Hellenic League ties. Athens responded to the call, sending out 4,000 men with Cimon at their head. However, something either in the behaviour or appearance of the Athenian force insulted the Spartans and they dismissed the Athenians, alone of all their allies. This action destroyed the political credibility of Cimon; he had already been under assault by his Athenian opponents led by Ephialtes, and shortly after this embarrassment he was ostracised. The demonstration of Spartan hostility was unmistakable, and when Athens responded, events spiralled rapidly into war. Athens concluded several alliances in quick succession: one with Thessaly, a powerful state in the north; one with Argos, Sparta's traditional enemy for centuries; and one with Megara, a former ally of Sparta's which was faring badly in a border war with Sparta's more powerful ally, Corinth. At about the same time, Athens settled the helots exiled after the defeat of their revolt at Naupactus on the Corinthian Gulf. By 460 BC, Athens found itself openly at war with Corinth and several other Peloponnesian states, and a larger war was imminent.