On the eve of the Peloponnesian War, the Hellenic world was divided between the respective alliance systems of Athens and Sparta, a geopolitical remnant of the wars against the Persian Empire. The system was bipolar, but it was not “balanced” owing to the vastly different characters of the predominant powers. Athens had acquired a maritime empire that provided revenue and external sources of food, while Sparta remained an agrarian society centered on the Peloponnesus. And though Sparta was a famously martial society, in terms of policy it was surprisingly unwarlike, with no expansionist tendencies and an almost lethargic attitude toward external affairs. Sparta’s legendary warrior tradition was a means by which to organize society rather than an instrument of policy and conquest. In contrast, Athens was aggressive and enterprising, attributes probably reinforced by its reliance on its empire for tribute and provisions. The speech of the Corinthian envoys to the Spartan assembly succinctly compare the natures of the two city-states:
The Athenians are addicted to innovation, and their designs are characterized by swiftness alike in conception and execution; you have a genius for keeping what you have got, accompanied by a total want of invention, and when forced to act you never go far enough. Again, they are adventurous beyond their power, and daring beyond their judgment, and in danger they are sanguine; your wont is to attempt less than is justified by your power, to mistrust even what is sanctioned by your judgment, and to fancy that from danger there is no release (1.70).
In the language of neorealism, Sparta was a “status quo” power and Athens was an “aspiring hegemon.” However, a fragile peace endured thanks to the independence of a lesser power, Corcyra, from either of the two alliance systems.