What positive outcome came from the Persian wars

At the time of the Persian Empire’s expansion into Greece,they had not been challenged until the Battle of Marathon when the defending Athenian army pulled a double envelopment tactic and crushed the Persians under King Darius while suffering only 192 casualties.Greece was the last country at the time that had a democracy type government controlling each of their own city states.If this governing system was to survive,the Greeks had to turn back the Persian hordes.Ten years later in 480 BC,the Persians again came,ready to crush all opposition,as at Marathon,when they came up against the Greek Phalanx,this time under Spartan King Leonidas’s leadership at thermopylae,they again suffered heavy losses until Persian King Xerxes,son of Darius,received information about a path that went around the Greeks,he exploited this and won the battle but eventually lost the war.The battle at Salamis and Plataea spelled defeat for the Persians and preserved the Greek way of life and in the long run dictated how things developed in that important part of the world which I think had a huge effect on how history was written.