In the speech which Thucydides put into the mouth of Pericles at the end of Book 1, successfully urging the Athenians not to submit to the Spartan demands, Pericles asserted his confidence that Athens could survive in war (1. 144. 1), and when Thucydides summed up Pericles' life he declared that this military estimate was sound. ‘When the war began, he appears in this matter too to have realized in advance the power of the city…and after his death his foresight with regard to the war was recognized still further’ (2. 65. 5f.). But was Thucydides right? Was Pericles' strategic estimate so justified by the war?

There is no real question of what Pericles' strategy was. Pericles himself set it out clearly enough (1. 143. 3–144. 1), and Thucydides reiterated it in the summing up (2. 65. 7). Nor has it ever been shown that it was plainly inept. Yet doubts remain. It was tried for so short a time that it cannot be thought to have been properly tested, and to commend it one is forced in some degree, like Thucydides, to argue the ineptitude of what replaced it. But perhaps all possible Athenian strategies might in the long run have failed. In any case it is hard to believe that so great a war could have been satisfactorily fought to a conclusion on a purely defensive strategy. Frustration is more likely to prompt invention and resource than to compel submission.