The causes of the Second Peloponnesian War, 431 – 404 BCE – Part Two: Athens’ treatment of Potidaea and the complaints of Aegina

Last time we spoke about the issue surropunding the Athenian alliance with Corcyra, and the deterioration in relations and descent into war between Corinth and Athens. Athens was as yet not at war with the Spartans, rather precariously placed instead, in a war with Corinth. The next major flashpoint occurred in consequence to the events with Corcyra. The Chalcidice
In 432, immediately after the events at Corcyra according to Thucydides, the Potidaeans were ordered by the Athenians to demolish one of their walls, give hostages to the Athenians, and to expel and no longer permit Corinthian magistrates to the city. Potidaea was founded by Corinth, and was a Corinthian colony based in the Chalcidice of Greece, but was subjected into the Athenian’s Delian League C458/7, and therefore was a tributary ally of Athens. Thucydides argues that the Athenians took these measures as a precaution against Corinthian subterfuge in the areas of vital importance to Athens, such as the Chalcidice and the Black Sea, where Athens imported much of her timber (essential for her shipbuilding) and grain supplies. Thucydides states that:
“It was feared that they might be persuaded by Perdicas [the Macedonian leader] and the Corinthians to revolt, and might draw the rest of the allies in the direction of Thrace [Modern European Turkey, Eastern Greece, and Bulgaria] to revolt with them. These precautions against the Potidaeans were taken by the Athenians immediately after the Battle of Corcyra.”
Thucydides is very defensive of the Athenian actions, and understandably so when we know of his background, yet the argument arises over the Potidaeans decision to approach both Athens and Corinth with delegations, the former in an attempt to persuade the Athenians to rebuff their demands, and the latter to gain support if Athens were to attack. Theoretically, if the treaty of 446 is stuck to, the Corinthians broke the truce by accepting the demands of the Potidaeans for support, and by helping a listed Athenian ally to revolt. This attempt to undermine the Athenians resulted in a force of 2000 Corinthian and Peloponnesian volunteers, not state directed, being sent to Potidaea, whilst the Athenians sent two forces, combined equalling 3000 hoplites and 70 ships. After a hard fought battle outside Potidaea between Potidaea, the Volunteers and their allies in the Chalcidice, and Athens, the latter emerged victorious and laid siege to the city, lasting into the outbreak of the Peloponnesian War in 431, and only coming to a conclusion in 429BCE.
What is interesting about this event is the persistence of the Corinthians to break the treaty of 446, and to attack Athens wherever she could. The Athenians were understandably aggrieved at the introduction of Corinth into what essentially was an internal Delian League dispute. Yet there was another event, against Aegina, which Thucydides alludes to, but does not provide any detail. Terry Buckley rightly defines this event as another major catalyst in the lead up to the outbreak of hostilities, and although it is still open to interpretation as to the reasons for the Aeginetan’s complaints in secret to the Corinthians, it is obvious that this had a factor on the eventual decision for war by the Spartans. It is possible the Aegina was a listed ally in the 446 treaty, or that she was unable or unwilling to pay the full amount of her tribute to Athens in 432, but what isn’t disputable is the fact that there was hostility and grounds for complaint by the Aeginetans.