An armistice between Athens and Sparta in 423 did not stop further northern places from falling into Brasidas’s arms—almost literally: at Scione the inhabitants came out to greet him with garlands and generally received him “as though he had been an athlete” (a rare Thucydidean glimpse of a world other than war and politics). He briefly won over Mende as well, but Athens recovered it soon after; Cleon arrived in 422 and won back Torone too. The deaths of both Cleon and Brasidas in a battle for possession of Amphipolis removed two main obstacles to the peace that most Spartans had been wanting for several years—in fact, since Sphacteria or even earlier (the return of Pleistoanax). As noted, the imminent expiry of the Argive peace was another factor, as was the occupation of Cythera, which provided a base for deserting helots (it is surprising that Athens did not make more use of the Spartan fear of their helots, a far from secret weapon of war). The essence of the Peace of Nicias (421) was a return to the prewar situation: most wartime gains were to be returned. Sparta had resoundingly failed to destroy the Athenian empire, and in this sense Athens, whatever its financial and human losses, had won the war.
The Peace of Nicias was seen by Thucydides as an uneasy intermission between two phases of a single war. Corinth and Boeotia rejected the peace from the outset, and an energetic young Athenian politician, Alcibiades, tried to return to what may have been Themistocles’ policy of stirring up trouble for Sparta inside the Peloponnese. Alcibiades’ plans, like those of Themistocles, centred on Argos, once again a factor in Greek international politics after 421 and ambitious to revive mythical Dorian glories. This was a period of low prestige and unhappiness for the Spartans, who were actually excluded from the Olympic Games of 420 by their enemies, the people of Elis; they waited 20 years before extracting revenge for this and other insults (but contrary to most modern views, the Olympic ban almost certainly did not last for the whole intervening two-decade period).
An alliance of Athens, Argos, Elis, and Mantinea fought Sparta in 418 in the territory of Mantinea. Sparta, resolute in war as it was irresolute in politics, scored a crushing victory over its enemies. The shame of the Sphacteria surrender was wiped out in one day, and the Greek world was reminded of Spartan hoplite supremacy. If Athens, whose finances were now strong again, wanted outlets for its aggression, it would have to find them elsewhere than in the Peloponnese. It sought it first in Anatolia, second on Melos, and third in Sicily. Athenian aggression outside the Peloponnese Entanglement with Persia
At some point after 425, when there was a routine renewal of the Peace of Callias, Athens began an entanglement in Anatolia with the Persian satrap Pissuthnes and subsequently with his natural son Amorges; it sent mercenary help to Pissuthnes and perhaps Amorges.
If this involvement began while the Archidamian War was still in progress, it was inexplicable provocation to Persia except on the assumption that Athens was too short of cash to pay these troops itself (a 1,000-talent reserve had been set aside at the beginning of the war, but there was resistance to touching it). If the entanglement began in the period of the Peace of Nicias, it was still dangerous adventurism because nobody could say how long the peace with Sparta would last. Harsh treatment of Melos
Thucydides says nothing about this Persian entanglement in its right place, despite its long-term importance: it was, after all, Persian intervention on the Spartan side that ultimately settled the outcome of the whole war. By contrast, he says a great deal about Athens’s expedition in 416 against ostensibly unoffending Melos. Although militarily trivial, the subjugation and harsh treatment of Melos certainly had moral implications, which Thucydides explores in the famous “Melian Dialogue.” It shows that the Athenians, who had made one attempt on Melos in 427 under Nicias, still wanted to round off their Aegean empire irrespective of the Dorian “ancestry” of Melos. Thucydides’ debate is framed in absolute terms, as if there were no question of provocation by Melos and the only issue were whether the weaker should submit to the stronger, as Melos in the end had to do. Yet there are points to be noted. First, Melos may have contributed to the Spartan war fund as early as 426. Second, Athens had assessed Melos at the high sum of 15 talents in the context of the (admittedly optimistic) general increase of 425; there was a fugitive sense in which Melos, which did not pay this exorbitant sum, could be seen as a recalcitrant subject. This, however, is not a line pursued by Thucydides’ Athenians in the “Melian Dialogue.” Third, some Athenian subject allies joined in coercing Melos in 416, evidence that Ionians and Aeolians could be mobilized against Dorians and perhaps even that they positively approved of all the implications of a notably ruthless action. And fourth, the Melians, unlike some other coerced subjects of the Athenians, were given a chance to submit but declined to take it. The Sicilian disaster
In 415 Athens turned to the third and most aggressive operation of the period, the great expedition against Sicily of 415–413, better known as the Sicilian disaster. The initial commanders were Alcibiades, Nicias, and Lamachus, but the expedition was weakened by the recall of Alcibiades to stand trial for impiety (he escaped and went to Sparta, which sent help to Syracuse at his suggestion).
Originally conceived in perfectly acceptable terms (a force of 60 ships to help Ionians and non-Greeks against the rising power of Syracuse), the expedition as ultimately sent was too ambitious; it consisted of a huge fleet of 140 ships—100 of them Athenian—reinforced by an additional 60. Thucydides speaks impressively but unspecifically about the cost of the expedition (he does report at one point that the Syracusans had spent 2,000 talents); an Athenian inscription is usually interpreted as showing that in a single transaction 3,000 talents was set aside for Sicily, though this restoration has been challenged.
A major problem was cavalry: Athens sent 250 cavalrymen without horses, but mounts were secured locally in Sicily, bringing the total to 650. (Athens also sent 30 mounted archers.) This total was not bad for a state that had never been a strong cavalry power, but it was scarcely more than half of the 1,200 that Syracuse was able to field. Even Athens’s early successes in the field, and there were some, were neutralized by that disparity: pursuit of the enemy by victorious Athenian infantry became a dangerous matter because of harassment by Syracusan cavalry. When the Spartan Gylippus arrived to help the Syracusans and Athens failed to wall in Syracuse, the Syracusan cavalry made the Athenian position intolerable: those who went out from their camps foraging for food often did not come back. Nicias himself was ill but was kept in post by the Athenians, a great mistake not compensated for by the arrival of first the more energetic Demosthenes and then Eurymedon. (Lamachus had been killed in action.) The final catastrophic sea battle in the Great Harbour of Syracuse was fought in cramped circumstances that did not allow the Athenian fleet enough freedom of maneuver. The expeditionary force was virtually annihilated, including its main commanders. The second phase of the war, 413–404
The blow to Athens’s morale and prestige was perhaps greater than the strictly military reverse, for, with an astonishing capacity for replacement, Athens managed, after a crash building program, to achieve rough naval parity with the Peloponnesians. This was the more remarkable in view of difficulties at home. Already before the end came in Sicily, Sparta had reopened the Peloponnesian War. On the advice of Alcibiades, the Spartans had fortified Decelea (413) and, as a result, were able to occupy Attica. Athens, embarrassed economically for that and other reasons, decided to impose a 5 percent tax on shipping instead of the tribute (but the tribute seems to have been restored in 410).