With Potidaea now under siege from Athens, Corinth, although unofficial involved, was looking to help save the city and their connection to it before it would fall. To do this, they would work with the surrounding cities on the Chalcidids to mount raids on the Athenians to help relive pressure on the city. However, their primary goal was to try and get Sparta to enter the conflict along with the other Peloponnesian cities. Corinth would convince their current allies to travel to Sparta to put their cases forward, while they would also travel to lead the argument for war.
Sparta would be forced to send out an invitation to members of the Peloponnesian league, inviting those who had been harmed by Athens. An assembly would be held where a number of cities would put their grievance to the Spartans. Corinth would have all their cities speak first to help set the mood before they would then stand and speak providing somewhat of the main event.
Athens had also sent representatives after learning of what was going to take place in Sparta, although they had not been invited. After Corinth had presented their case Athens would ask the Spartans if they could address the assembly. However, Athens was not looking to address the specific charges laid against them, but rather urge Sparta to think long and hard about the decision they would come to. They would highlight the gravity of what war would mean, especially with a city state such as themselves.
To round out the assembly, the Spartans would dismiss all the various representatives so they could discuss the matter between themselves. This would then see speech’s given by King Archidamus, representing the peace part and an ephor from the war party. After they had spoken the Spartans would vote on if they thought Athens had breached the 30 years peace where it quickly became clear Sparta was in the mood for war, a departure from the policies of the peace party that had dominated Spartan politics for most of the past 50 years.