" Just as we do not today differentiate between the Roman Republic and the imperial period of the Julio-Claudians when we think of the Roman Empire, so in the future no one will bother to make a distinction between the British Empire-led and the American-Republic-led periods of English-speaking dominance between the late-eighteenth and the twenty-first centuries. It will be recognized that in the majestic sweep of history they had so much in common--and enough that separated them from everyone else--that they ought to be regarded as a single historical entity, which only scholars and pedants will try to describe separately. "

― Andrew Roberts , A History of the English-Speaking Peoples Since 1900