Cleon's success at Sphacteria put an end for the time to all hopes of peace. Athens, now encouraged to fresh hopes and ambitions, began the eighth year of the war with new attempts to carry hostilities into the country of her adversaries. She made an attack on Megara, and, though failing to capture the city itself, got possession of the harbour. This was followed up by the invasion of Bœotia. Thirty-three years before Athens had acquired, and had retained for nine years, an ascendency over this country. This ascendency she had never given up the hope of regaining, a hope that was built, it must be remembered, not so much on superiority of force as on the enmity of the Bœotian towns to Thebes. Here, as almost everywhere else in Greece, party divisions counted for much. Thebes was governed by an oligarchy; in each dependent town there was a democratic party anxious for its downfall, and looking to Athens to effect it. It is not within my province to tell the story of the campaign. It will suffice to say that the attempt failed, and failed disastrously. The Athenians were defeated in a great battle at Delium, with the loss of the general in command and a thousand heavy-armed troops. Later on in the same year they suffered greatly in Thrace, where, through the energetic action of Brasidas, by far the ablest Spartan of the time, they lost many valuable dependencies, the most important of which was Amphipolis.
It will be easily imagined that a year which had opened with such high hopes found the Athenians at its close in a very different temper of mind. The war party was greatly discouraged; the friends of peace, of whom, it will be remembered, Nicias was the leader, were proportionately strengthened. Sparta was still anxious to bring the war to an end. Its government had sanctioned the expedition of Brasidas against the Athenian dominion in Thrace in the hope that if it should be successful it might work for peace. Its dominant motive was the desire to recover the Spartan prisoners at Athens. Many of these belonged to the first families in the state, and had powerful friends, who were ready to use every means to bring about their release. Brasidas, on the other hand, full as he was of ambitious schemes, and Cleon, who may possibly have hoped, on the strength of his success at Sphacteria, for military distinctions in the future, were strongly opposed to peace.
Grote thinks, and very likely is right in thinking, that both the political leaders at Athens were wrong; Cleon in advising the people to insist on terms which it was impossible for Sparta to grant, Nicias in failing to urge them to make a vigorous effort to save what remained, and to recover what had been lost, of their dominion in Thrace. The terrible loss at Delium, falling largely, as it did, on Athenian citizens, made vigorous counsels unwelcome, and Nicias, who, though personally brave, had but little moral courage, was not the man to give them.
The immediate result was a compromise. It was not found possible, at least for the time, to agree upon terms of peace, but a truce for a year was made. This was sworn in what in our calendar is March. Two days afterwards the Athenian dependency of Scioné in Thrace revolted to Brasidas. This general had just made arrangements to secure his new ally, when commissioners arrived to announce to him the conclusion of the truce. The news was most unwelcome to him. Scioné he aboslutely refused to surrender, and, to justify his refusal, positively asserted that it had revolted before the truce was sworn. The Athenian commissioner, however, had no difficulty in satisfying himself of the real facts of the case, and he sent home a despatch in which he stated them.
A fierce and, it must be allowed, a perfectly justifiable outburst of anger was the result. There was no desire to disturb the working of the truce elsewhere, but at the same time there was a resolute determination to recover Scioné, and to punish it severely for its revolt, Cleon proposing that, in the event of its recapture, all the male inhabitants should be put to death. Popular feeling was further exasperated by the news of the revolt of another town in Thrace, Mendé by name. The recovery of these towns was a matter on which all parties were bound to agree. Nicias was for the time on the same side as Cleon, and went out in command of the expedition, a certain Nicostratus being his colleague. They had with them fifty ships of war, 1000 heavy-armed troops; about as many light-armed, and 1000 Thracian mercenaries. Mendé was recovered. An assault failed, Nicias, who led one of the attacking parties, being wounded; but, soon afterwards, a popular movement put the place into the hands of the Athenians. The majority of the inhabitants had been adverse to the revolt. Scioné was closely invested, and Nicias, leaving a division to guard the lines, returned with the armament to Athens.
In March 421 the year's truce expired. The condition of affairs in Thrace made peace impossible, but there was no immediate resumption of hostilities. In August, however, Cleon prevailed upon the Athenians to make a vigorous effort to recover what had been lost in Thrace. Nicias, we may he sure, led the opposition. Whether, as Grote supposes, he was one of the generals of the year, and refused to serve when the Assembly resolved on sending an expedition, is more doubtful. It can hardly be supposed that the generals had it in their power to go or not to go as they pleased. The case of Sphacteria was evidently exceptional, something, we may almost say, of a huge practical joke. It is more likely that Cleon was in office, and that he hoped, though hardly, I should suppose, without misgivings, that he might be victorious. It is not part of my task to give the details of the campaign. The result was that the Athenians suffered a crushing defeat, losing 600 heavy-armed in killed and missing. Cleon was among them. On the other side there were but seven men killed, but one of the seven was Brasidas.
The death of these two men removed the principal obstacles to peace. Sparta was still as anxious as ever for it, and Athens, after this second disaster, which was scarcely less damaging than the defeat at Delium, had begun to look upon it as a necessity. A conference of the allies of Sparta was held at that city, and this was attended by envoys from Athens, among whom Nicias was the most important and influential. The discussion was prolonged. At first both sides made impossible demands, and at one time the prospects of a successful conclusion were so small that the Spartan government made, or, at least, threatened to make, preparations for an invasion of Attica in the spring. The point chiefly in dispute was the territory acquired during the war. Finally, it was agreed that each party should surrender what it had acquired by force. On the term 'force' a narrow interpretation was put. Platæa, which had surrendered, was not given back to Athens; Athens, on the other hand, kept the Megarian and Corinthian towns which had capitulated to her. A peace for fifty years was concluded in March 421. Nicias was one of the Athenian commissioners who swore to it, and it was generally known as the 'Peace of Nicias.'
Some of the allies of Sparta were discontented with the terms agreed upon, and refused to accept the vote of the majority. For this and for other reasons it was soon made evident that the arrangement was far from satisfactory. Difficulties started up at once. It had been agreed to decide by lot which of the two contracting parties should be the first to fulfill its part of the conditions. Athens gained the choice, an advantage so great that Nicias is accused by Theophrastus of having secured the result by a bribe. The Spartans immediately released all the Athenian prisoners in their possession, and sent envoys to Clearidas, their commander in Thrace, with directions that Amphipolis and the other revolted dependencies of Athens should be delivered up to that state. Clearidas declared that it was not in his power to fulfill this stipulation, and went back with the envoys to explain the situation. He was sent again with peremptory orders to carry out his instructions. If the towns still refused to submit, he was to remove the Lacedæmonian garrisons. This he did, but Athens did not recover her Thracian possessions. At the same time the dissatisfied allies of Sparta came back with fresh instructions from home to protest against the peace.
Sparta was now in a very embarrassing position. She could not fulfill her part of the terms, and consequently she could not ask for the prisoners. At the same time she dreaded a new combination of parties. Argos had stood aloof from the war, and was now, with her strength unimpaired, a formidable power. A thirty years' truce that she had concluded with Sparta was drawing to an end. If she was to ally herself with Athens, the consequences might be serious. The Spartan government now proposed a new arrangement to Nicias and his colleagues (they had remained in Sparta, waiting, it would seem, for the fulfillment of the conditions). Let Athens and Sparta come closer together—become, in fact, allies. And this was done. A defensive alliance was formed; each party bound itself to assist the other in case it should be attacked. This was the single provision of the treaty. It was specified, however, as a case coming under this provision, that the Athenians should give their most energetic help in repressing any insurrection of the Helots that might take place in Laconia. A further condition, not expressed in the treaty, but secretly agreed upon, was that the Sphacterian prisoners should be at once given up. This last was immediately carried out.
Nicias has been severely criticised for having been a party to the conclusion of a peace so little advantageous to his country. And it must be confessed that the criticism is just. He and his colleagues ought to have insisted, as a necessary preliminary, on the restoration of the Thracian towns. It might be true that the Spartan force in those regions was not strong enough to compel the towns to return to their Athenian allegiance; but if, as Grote urges, Sparta and Athens had combined in an energetic effort to compel submission, the towns could not have long resisted. From this point of view, the withdrawal of the garrisons was a mistake. With a besieging force outside, and a garrison within, under peremptory orders to assist not the defence but the attack, surrender would have been inevitable. We can only suppose that Nicias and his friends fairly lost their heads when they saw a chance of what they had never ventured to hope for—an actual alliance with Sparta. After this, they may well have thought, perpetual peace was almost assured. As a matter of fact, the peace and the treaty which followed it were doomed from the beginning to a speedy end.
It is needless to describe the obscure and perverse politics which occupied the Greek States during the period that followed the conclusion of the peace of Nicias. There was little or no inclination in either Athens or Sparta honestly to fulfill their obligations. If there had been, it would probably have been defeated by the unprincipled action of statesmen seeking to advance personal or party aims. It is possible, for instance, that Sparta intended to do right when she sent envoys to Athens to discuss, and, if possible, to arrange the matters in dispute, though one at least of their demands was highly unreasonable. But they were shamefully tricked by Alcibiades, with the result of making them seem absolutely unworthy of trust. Nicias had introduced them to the Senate. There they had declared that they came with full powers to settle, and had made a very favourable impression by their moderation and reasonableness. Alcibiades, whose object it was to ally Athens with Argos, began to fear that an arrangement might be made with Sparta. Accordingly, he went to one of the envoys, with whose family he had an hereditary friendship. 'You will find,' he said, 'the Assembly far less reasonable than the Senate. If it is known that you have full powers to treat, it will seek to intimidate you, and to extort, by fear or force, concessions which you are not authorised to make. It will be better, therefore, to say that you have come with no powers, but only to explain and discuss. The people will listen calmly and quietly. I myself will support you as strongly as I can, and have no doubt that I shall be able to obtain the consent of the Assembly on the doubtful point of Pylos.' The envoys naturally fell into the trap, not saying a word about the matter to Nicias, though he was certainly the foremost friend of Sparta in Athens, and was probably, as Grote suggests, their own host. The Assembly met. Do you come with powers to treat?' asked Alcibiades of the envoys. They answered as they had been instructed, 'No; only to discuss and explain.' Nicias, the Senate which had heard from the men's own lips an exactly contrary statement, and the Assembly generally, which had in fact met under the impression that the affair could be settled then and there, were astonished and indignant. Alcibiades himself made a furious speech denouncing Spartan duplicity, and seized the opportunity of proposing that the envoys from Argos should be called in. This would have been done, had there not occurred at the moment the shock of an earthquake. On this the Assembly was, as usual, dismissed. Of the conduct of Alcibiades it is needless to speak. The Spartans, though, perhaps, more sinned against than sinning, gave another proof of the bad faith which was characteristic of their diplomacy. As for Nicias, his reputation as a sagacious politician must have suffered greatly. He was disgraced along with the clients whose cause he had espoused.
With this unpopularity may be connected a curious incident which occurred about this time. The demagogue Hyperbolus, a feeble successor of Cleon, conceived the idea that one or other of the two politicians with whom he contended on unequal terms might be got rid of by the method of ostracism. But he was 'hoist with his own petard.' The persons threatened combined against their adversary, and when the votes were counted it was found that the person named was Hyperbolus himself. He was banished accordingly, but it was felt that he was too insignificant a person to have so formidable an engine directed against him. The engine itself was discredited, and was never again employed in Athenian politics.