Fear -- and the Ukrainian War Prologue Thucydides says that fear sparked the Peloponnesian War. Fear was behind Sparta’s attack on Athens. In the 50 years or so after the Persian wars, 479-431 BCE, Sparta watched the rise of Athenian power with grave concern – and fear. This was the main reason for the breakout of the Peloponnesian War in 431 BCE. The united forces of Sparta and Athens, and their Greek allies, defeated the vast armies and navies of the Persian Empire in early fifth century BCE. At the end of the Persian wars and the expelling of the Persians from Greece, Athens, and Sparta parted ways. Sparta remained the Greek superpower in Peloponnesos. It refused, however, to join Athens in protecting Hellas, Greek poleis (city-states) spread all over the Mediterranean, from the Persians. Athens founded the Delian League in Apollo’s sacred island of Delos in the Aegean and close to the Ionian coast dotted by Greek poleis. The Per...