Eurasia was conducive to civilization due to its unique geography. At least that's Jared Diamond's argument in Guns, Germs, and Steel (Amazon.com: Guns, Germs, and Steel: The Fates of Human Societies (9780393317558): Jared M. Diamond: Books). read more
If the Fertile Crescent hadn't come first, it would have been some other civilization with similarly favorable geographic conditions, but the point is that this would not have been possible outside Eurasia. read more
The ancient countries of the Fertile Crescent, such as Sumer, Babylonia, Assyria, Egypt, and Phoenicia, are regarded as some of the world’s earliest complex societies. read more