Was the Peloponnesian War inevitable after 435 BC?
By Lukas Lemcke
Tiresias, Vol.1 (2012)
Abstract: Based heavily on the account of the Greek historian Thucydides, the paper outlines the events leading up to the outbreak of the 2nd Peloponnesian War in 435, and analyzes whether the outbreak of the war was inevitable, i.e. if the political conditions in Greece would have led to war no matter what the specific events were that, in the end, were the straw that broke the camel’s back.
Introduction: In 435 BCE, Corinth, a member of the Peloponnesian league, first clashed with Athens. This specific episode (Thuc. 1.24-55) concerns the city of Epidamnus, a colony of Corcyra, which, in turn, was a colony founded by Corinth. When Epidamnus asked for support due to domestic problems and enemy attacks, Corinth responded and thereby angered Corcyra. In the ensuing conflict between the latter two, Corinth was defeated and subsequently equipped an even larger force to stage an attack on Corcyra. Both then sent embassies to Athens to plead their cases. Athens was finally convinced by the Corcyrean diplomats and decided to send a token force. With Athenian help, Corcyra defeated the Corinthian forces, forcing them to retreat.
The Athenians realized that a total alliance with Corcyra and the ensuing warfare with Corinth would “constitute a breach of the treaty with the Peloponnese,” so they decided to establish a defensive alliance to keep Corcyra’s powerful navy from falling into Corinthian hands, which would have left Corinth with a navy that could rival that of Athens. In legal terms, the Thirty Years’ Peace allowed any city that was not part of an alliance at the time of the conclusion of the treaty to ally itself with whichever side it chose. In that respect, Athens certainly had the right to ally itself with Corcyra without breaking the treaty. However, since an alliance at this point served only “to injure other powers,” the defensive alliance “broke the spirit if not the letter of the Thirty Years’ Peace.” Nonetheless, the Athenians at this point had accepted the fact that a war with the Peloponnese was dawning, and that, therefore, they ought to try to prepare themselves as best they could – thereby engaging in the same kind of provocative behaviour that had caused the First Peloponnesian War.
This episode is followed in the early 430s BCE by the dispute over Potidaea (Thuc. 1.56-66), another Corinthian colony that was allied with Athens but received annual magistrates from Corinth. To prevent a revolt, Athens demanded the expulsion of the city’s Corinthian magistrates and the dismantling of its fortifications. Potidaea sent embassies first to Athens to try and dissuade them from their demands and then to Sparta, accompanied by Corinthians, to ask for support should Athens attack. The former failed, the latter was granted. When the revolt started, Sparta nonetheless decided against taking action, thereby breaking its oath. The fight around Potidaea was eventually won by Athens, and the city was then besieged and cut off from supplies by land and sea. As with Corcyra, only a breach of the peace treaty would constitute a legal offence against the Peloponnesians. Scholars have argued for the existence of an autonomy clause in the Thirty Years’ Peace that would guarantee Athenian non-intervention in the domestic affairs of its allies, but the truth of this theory has not been ascertained to date.
If, however, for the sake of argument, such an autonomy clause did exist, Athens was most certainly breaking the treaty. On the other hand, the rather harsh Athenian demands might have been provoked by the Corinthians’ thinly veiled intention of stirring up trouble among the Athenian allies, and Sparta could, therefore, have interpreted it as a pre-emptive measure against Corinth. Athens then hoped that Sparta would understand this notion and would not be provoked into war. However, this attempt to limit the conflict to Athens and Corinth was unsuccessful, as Sparta would not continue to sit by idly and watch events unfold.