Snake Featherston
Banned
Greek civilization would not have survived a Persian conquest. Materially and economically, they would have been just fine. Indeed, they might have actually been more prosperous under Persian rule than they were IOTL. But the most important qualities of Greek civilization were a product of political disunity and the institution of the assembly, which would have either vanished or been reduced to irrelevance under Persian rule.
They also vanished under the Macedonian kingdoms and Roman rule, but nobody says the Diadochi or Romans killed Greek civilization.