Makes no sense in economics, the whole history since industrialization is that the economy gets bigger and bigger, both in absolute terms and per capita.
The position in the world will. At its peak, Britain was truly the empire on which the sun never sets, but these colonies were not assimilated by British culture to become part of Britain. Therefore, they were ultimately lost. Britain will eventually revert to the position befitting a small island nation—insignificant in the realm of geopolitics.
