History of the Peloponnesian War

The ambassadors were instructed also to say that, if the Athenians had wished to do wrong, they would already have made the Argives allies, as their envoys were present for that very purpose;

and any other complaints which they had to make they included in their instructions to Nicias and his colleagues and then despatched them to Sparta. When these had arrived and had finished reciting their other demands, they said in conclusion that, unless the Lacedaemonians should give up the alliance with the Boeotians, in case these would not accede to the treaty, they themselves would make an alliance with the Argives and their confederates. But the Lacedaemonians refused to give up the alliance with the Boeotians— the party of Xenares the ephor and all the rest that were of that view carrying their point to this effect—but the oaths they renewed on Nicias' request; for he was afraid that he would return with nothing accomplished and be exposed to calumny, as indeed happened, since he was generally regarded as having been responsible for the treaty with the Lacedaemonians.

On his return, when the Athenians heard that nothing had been done at Lacedaemon, they flew into a rage, and thinking they had been wronged, when Alcibiades brought in the Argives and their allies, who chanced to be present, they made an alliance with them on the following terms: