Their concluding argument, however,

Their concluding argument, however, has greater effect: "To sum up as succinctly as possible both in general and in particular, one point instructs you not to abandon us, namely: There are three significant naval forces in Greece, ours, your own, and the Corinthians'. If you allow two to combine into one and if the Corinthians beat us, you will have both the Corcyrean and Peloponnesian navy to fight against. But if you ally with us, you will engage them with a larger number of ships-ours" (1.36.3). After hearing the counterarguments of the Corinthians, the Athenians decide to make a purely defensive alliance with Corcyra. Their reasons, as reported in chapter 44, have nothing to do with the justice of the case, but are precisely those practical considerations advanced by the Corcyreans at the end of their speech: "For they thought that the war with the Peloponnesians was going to take place and they did not want to abandon a navy as significant as the Corcyrean to the Corinthians, but to let them collide with each other as much as possible so that they would enter into the war, if it were necessary, with weaker opponents whether Corinthians or any other naval power" (1.44.2). Thucydides then adds a further point, also adduced by the Corcyreans in their speech: At the same time the island seemed to them well situated for a naval expedition to Italy and Sicily. Such a consideration is fully appropriate in the diplomatic climate of the pre-war years for we know that Athens at this time was concerned with western Greece. But from a post-war perspective the words take on an added force. Inevitably they bring to mind Corcyra's later role as the marshalling point for the great expedition that then passed along the Italian coast to Sicily and ultimately to defeat at Syracuse. For a second, just in passing, we detect a flicker of irony--what seemed to them an advantage turns out to be a step toward disaster.