Both sides at length grew weary of the war, and in 421 a truce for fifty
years was concluded, which, though ill kept, and though many of the
confederates of Sparta refused to recognize it, and hostilities still
continued in many parts of Greece, protected the Athenian territory from
the ravages of enemies, and enabled Athens to accumulate large sums out
of the proceeds of her annual revenues. So also, as a few years passed
by, the havoc which the pestilence and the sword had made in her
population was repaired; and in 415 Athens was full of bold and restless
spirits, who longed for some field of distant enterprise wherein they
might signalize themselves and aggrandize the state, and who looked on
the alarm of Spartan hostility as a mere old-woman's tale. When Sparta
had wasted their territory she had done her worst; and the fact of its
always being in her power to do so seemed a strong reason for seeking to
increase the transmarine dominion of Athens.

The West was now the quarter toward which the thoughts of every aspiring
Athenian were directed. From the very beginning of the war Athens had
kept up an interest in Sicily, and her squadron had, from time to time,
appeared on its coasts and taken part in the dissensions in which the
Sicilian Greeks were universally engaged one against the other. There
were plausible grounds for a direct quarrel, and an open attack by the
Athenians upon Syracuse.

With the capture of Syracuse, all Sicily, it was hoped, would be
secured. Carthage and Italy were next to be attacked. With large levies
of Iberian mercenaries she then meant to overwhelm her Peloponnesian
enemies. The Persian monarchy lay in hopeless imbecility, inviting Greek
invasion; nor did the known world contain the power that seemed capable
of checking the growing might of Athens, if Syracuse once should be
hers.