Paul's written before on the uniqueness of the valley.

A key that America has is her ability to allow for iterative steps ( which often pose as failure ) before a great idea can execute commercially. Other countries seemingly have deeper social stigma associated with failing and philistine impatience. This could be changing though at rates faster than perceived within the valley.

http://en.wikipedia.org/wiki/Renaissance is a great study. In particular, characteristics asymptotic re innovation.

" They say that coming events cast their shadows before " - Ada, countess of Lovelace