What effect did the Peloponnesian War have on subsequent events in Greece?
The Peloponnesian War weakened Greek’s greatest powers and the war’s chief adversaries, Athens and Sparta. While we can’t be sure of this, I think it’s fair to say that if the war had not happened, and Athens and Sparta had maintained their strength, it would have been much harder for Philip II of Macedon to come in and conquer Greece. If Philip II of Macedon had failed at that, Alexander the Great wouldn’t have had Greece as his launching pad, he might never have created his empire, and the world would be a different place today.