That Athens was a dissatisfied powe

That Athens was a dissatisfied power, that she was not happy with the results of the First Peloponnesian War (which forced her to withdraw from territory that had opened her way to the Ionian Sea), that Sparta knew it, that Corinth was obsessed by it--this is why the war was inevitable. The Second Peloponnesian War was inevitable because of the inconclusiveness of the first. Athens would not give up her ambitions without a decisive defeat, which she had not received: Sparta would not let her fulfill them without a fight to the finish. Ste. Croix complains that it was none of her (Sparta's) business, that she wasn't directly threatened. We must remember ( and so should he) that, in the first war, the Athenians had expanded into the Peloponnese. The Peloponnese was Sparta's security zone. The Spartans would fight rather than admit the remote possibility of that happening again. Ergo, war was inevitable.