History of the Peloponnesian War

There was this further disadvantage: the bringing in of provisions from Euboea, which had formerly been managed more expeditiously by way of Oropus overland through Deceleia, now became expensive, the route being by sea round Sunium. Everything alike which the city needed had to be imported, and Athens ceased to be a city and became a garrisoned fortress.

For the Athenians had to keep guard at the battlements, during the day by relays, but at night everybody except the cavalry, some doing duty at the watch-posts, others upon the wall, both summer and winter, and so suffered great hardships. But what weighed most heavily upon them was that they had two wars on their hands at the same time;

and yet they had been brought to such a pitch of determination as no one would have credited before it happened, if he had heard of it. That they, who were themselves being besieged by the Peloponnesians by means of a fortress in their country, should not even thus abandon Sicily, but should in turn be there besieging Syracuse in the same manner, a city which taken by itself is not smaller than the city of Athens; and that they should have caused the Hellenic world to make so amazing a miscalculation of their power and daring —inasmuch as at the beginning of the war some thought that they could hold out one year, others two years, others longer but never more than three years, if the Peloponnesians should invade their country—that in the seventeenth year after the first invasion of Attica they should have gone to Sicily, when already war-worn in all respects, and should have undertaken another war no whit less serious than that which was already being waged with the Peloponnesus—this, I say, was incredible.