History of the Peloponnesian War

The Lacedaemonians, on the other hand, wished for peace, because they found protracted beyond their expectation those hostilities by which they imagined that in a few years they should reduce the power of the Athenians, if they ravaged their land; and because they had met with the disaster on the island—such as had never yet befallen Sparta: and in consequence of their country being plundered from Pylus and Cythera; while their helots also were deserting, and there was a constant apprehension lest even those that remained in the country, trusting in the support of those who were out of it, should, on the strength of the present state of things, adopt some revolutionary designs against them, as on a former occasion.

It happened, too, that their thirty years' truce with the Argives was on the point of expiring, and the Argives would not renew it, unless the Cynurian territory were restored to them; so that it appeared impossible for them to carry on war at once with the Argives and Athenians. Besides, they suspected that some of the states in the Peloponnese would revolt from them to the Argives; as was really the case.