Please help me understand ...

"Martin Wolf, the famed economics columnist for the Financial Times ... offered a deeper cultural contrast worth pondering. 'The British are definitively post-superpower in their attitudes,' he said. 'This is not the same as being post-nationalist, as our relationship with the E.U. demonstrates. But the British do not demand self-sufficiency, even in this apparently crucial policymaking position. The U.S. is of course nationalist, far from ‘post-superpower,’ and quite sure that it has the best of everything."

--Matt Miller, "Canada takes over the U.K. economy," Washington Post