The Potidaeans, who inhabit the isthmus of Pallene, being a Corinthian colony, but tributary allies of Athens, were ordered to raze the wall looking towards Pallene, to give hostages, to dismiss the Corinthian magistrates, and in future not to receive the persons sent from Corinth annually to succeed them.

It was feared that they might be persuaded by Perdiccas and the Corinthians to revolt, and might draw the rest of the allies in the direction of Thrace to revolt with them.
These precautions against the Potidaeans were taken by the Athenians immediately after the battle at Corcyra.

Not only was Corinth at length openly hostile, but Perdiccas, son of Alexander, king of the Macedonians, had from an old friend and ally been made an enemy.

He had been made an enemy by the Athenians entering into alliance with his brother Philip and Derdas, who were in league against him.

In his alarm he had sent to Lacedaemon to try and involve the Athenians in a war with the Peloponnesians, and was endeavouring to win over Corinth in order to bring about the revolt of Potidaea.