Zhou Enlai is famously supposed to have observed that the passage of two centuries provided insufficient historical perspective from which to judge the consequences of the French Revolution.

Fareed Zakaria is unencumbered by such modesty. He doesn't need 200 years to elapse before feeling confident enough to make sweeping judgements. He reckons he can spot the arrival of a whole new epoch barely half a decade after it has started.

This historical perspicacity provides the central contention of his latest book. There have been three ‘tectonic’ changes in world history in the last 500 years (only three?), Zakaria says: the rise of the West in the fifteenth century; the rise of the United States at the end of the nineteenth