History of the Peloponnesian War

Lacedaemon, on the other hand, found the event of the war falsify her notion that a few years would suffice for the overthrow of the power of the Athenians by the devastation of their land. She had suffered on the island a disaster hitherto unknown at Sparta; she saw her country plundered from Pylos and Cythera; the Helots were deserting, and she was in constant apprehension that those who remained in Peloponnese would rely upon those outside and take advantage of the situation to renew their old attempts at revolution.

Besides this, as chance would have it, her thirty years' truce with the Argives was upon the point of expiring; and they refused to renew it unless Cynuria were restored to them; so that it seemed impossible to fight Argos and Athens at once. She also suspected some of the cities in Peloponnese of intending to go over to the enemy, as was indeed the case.