History of the Peloponnesian War

And the Lacedaemonians, seeing they refused, dismissed them and by themselves entered with the Athenians into a league, because they imagined that the Argives would not renew their peace (because they had refused it before when Ampelidas and Lichas went to Argos, and held them for no dangerous enemies without the Athenians); and also conceived that by this means the rest of Peloponnesus would not stir; for if they could, they would turn to the Athenians.

Wherefore the ambassadors of Athens being then present, and conference had, they agreed; and the oath and league was concluded on in the terms following: