History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
They were afraid, too, of their allies, lest, elated over these failures of theirs, the revolt among them might spread, and they repented that they had not come to terms when a good opportunity offered after the affair at Pylos.
The Lacedaemonians, on the other hand, favoured peace because the war was turning out contrary to their hopes. They had expected that in a few years, if they should ravage their territory, they could pull down the power of the Athenians; whereas they had met with the calamity on the island of Sphacteria, such an one as had never before befallen Sparta; their territory was ravaged from Pylos and Cythera; the Helots were deserting, and always there was apprehension that those who remained, relying on those beyond the border,[*](ie. those who had escaped.) might revolt in the present state of affairs, just as they had done before.[*](The great revolt of the Helots, called the Third Messenian War; cf. 1.101.-1.103)