It was a nasty little regional war, with combat from Sicily to the Hellespont, lasting (with poorly adhered-to truces) for 27 years, involving all the great Greek states (wealthy farming Thebes and oligarchic commercial Corinth as well as the better-known war-geek Sparta and art-for-our-sake imperial/democratic Athens), and many smaller ones, often involuntarily, with brutal massacres, sieges, ethnic cleansings, dramatic turnarounds, and plagues. Being written about by Thucydides sealed its interest for well over two thousand years.
The Peloponnesian War was popular during the Cold War, since it asked various questions of interest, like:
- Can a democracy successfully fight a long war that requires a lot of sacrifice from its population? (Answer: yes, extremely well, but you don't want to be a general in its army or navy. If you fail they execute or exile you, and if you succeed they fete you, then become suspicious of you and execute or exile you)
- If the main path to victory is blocked by a determined opponent, should you try striking in an unexpected place? (Answer: often it's unexpected because it's dumb. Try to avoid high-risk enterprises that, even if successful, have minimal payoffs. We should all fear a Syracusan Expedition, but instead find the concept of a surprise end-run around a stalemate irresistable.)
- Can terrorizing civilian populations and destroying resources win a war without crushing the opponent's main force? (Answer: no, but it has a weird sort of satisfaction that can become dangerously addictive.)
- Who is more effective at war, determined tyrannies or fractious democracies? (Answer: the judgments of battlefields can be fickle, and chance can play a large role. But no matter who wins, democracies have staying power: Athens lost, and then regained its prosperity and dominance--before losing all to Philip of Macedon and his nasty little boy, Alexander, in the next century.)
Victor Davis Hanson's A War Like No Other taught me a lot about the ground level truth of that war. Highly recommended to anyone trying to depict realistic state-level combat with Classical-era edged weapons. It's a painful, bloody grind. You have to watch your back as well as your front, and you may do everything right and still die of plague.