Thucydides, History of the Peloponnesian War
Benjamin Jowett, Ed.

46. The trick which had deceived the Lacedaemonians themselves completely deceived Nicias,¹ who could not understand the disavowal of their powers. Nevertheless in the assembly which met on the following day he still continued to maintain that the Athenians ought to prefer the friendship of Sparta, and not to conclude the Argive alliance until they had sent to the Lacedaemonians and ascertained their intentions. He urged them not to renew the war now, when it could be put off with honour to themselves and discredit to the Lacedaemonians; they were successful and should seek to preserve their good fortune as long as they could, but the Lacedaemonians were in a bad way, and would be only too glad to fight as soon as possible at all hazards. [2] And he prevailed on them to send envoys, of whom he was himself one, requiring the Lacedaemonians, if they were sincere in their intentions, to rebuild and restore Panactum, to restore Amphipolis, and to renounce their alliance with the Boeotians unless they came into the treaty, according to the stipulation which forbade the contracting parties to make a new alliance except by mutual consent. [3] If we, they added, had wanted to deal unfairly, we should already have accepted an alliance with the Argives, whose ambassadors have come hither to offer it. [4] They entrusted the representation of these and their other grievances to Nicias and his colleagues, and sent them away to Sparta. These, on their arrival, delivered their message, which they concluded by declaring that, unless the Lacedaemonians renounced their alliance with the Boeotians in case the latter still refused to accept the peace, the Athenians on their part would enter into an alliance with the Argives and their confederates. The Lacedaemonians refused to give up their Boeotian alliance, Xenares the Ephor, with his friends and partisans, carrying this point. However they consented to ratify their former oaths at the request of Nicias, who was afraid that he would return without having settled anything, and would incur the blame of failure, as indeed he did, because he was held to be responsible for the original treaty with the Lacedaemonians. [5] When the Athenians learned on his return that the negotiations with Sparta had miscarried, they were furious; and acting under a sense of injustice, entered into an alliance with the Argives and their allies, whose ambassadors were present at the time, for Alcibiades had introduced them on purpose. The terms were as follows:—