History of the Peloponnesian War

The Argive magistrates, on hearing the proposals, reported them to their government and people, and the Argives passed the decree and chose twelve men with whom any of the Hellenes who pleased might conclude an alliance, except the Athenians and the Lacedaemonians; neither of these should be allowed to make a treaty with Argos without the express consent of the Argive people.

These proposals the Argives accepted the more readily, in the first place because they saw that they should have war with the Lacedaemonians—for the treaty with them was on the point of expiring—and, moreover, because they had hoped to secure the hegemony of the Peloponnesus. For at this time Lacedaemon had fallen into very ill repute and was despised on account of its misfortunes, while the Argives had attained an excellent position in all respects, having had no part of the burden of the war with Athens, but rather, as they were at peace with both parties, having reaped a harvest from it.

Thus the Argives were ready to receive into their alliance any of the Hellenes that were so inclined.

The Mantineans and their allies were the first to join them, through fear of the Lacedaemonians. For a part of Arcadia had been reduced to subjection by the Mantineans, while the war with the Athenians was still going on, and they thought that the Lacedaemonians, now that they had leisure, would not suffer them to retain their sovereignty. So they turned gladly to Argos, regarding it as a powerful state, one always at variance with the Lacedaemonians, and under a democratic form of government like themselves.

And when the Mantineans had revolted, the rest of the Peloponnesus also began to mutter that they must do the like, thinking that the Mantineans had changed sides because they possessed some superior knowledge. At the same time they were angry with the Lacedaemonians on other grounds, and especially because it was written in the treaty with Athens that it would be consistent with their oaths to add or take away whatever shall seem good to both states, that is, to the Lacedaemonians and Athenians.

For it was this article especially that was disturbing the Peloponnesus far and wide and causing suspicion that the Lacedaemonians wished in concert with the Athenians to reduce them all to slavery; for it would have been just, they thought, that the clause should have given the power to alter the articles to all the allies.