"In the whole politics of Greece, the anxiety, with regard to the balance [of power], is most apparent, and is expressly pointed out to us, even by the antient historians. Thucydides represents the league, which was form'd against Athens, and which produc'd the Peloponnesian war, as entirely owing to this principle."
January 1, 1970
https://en.wikiquote.org/wiki/Thucydides