Two arguments on why it won’t happen, and eve it does to a certain degree, it won’t matter.
Apparently, severe population decline is very limited to certain regions, also mentioned here last week.
There will be countries and regions that will suffer long-term depopulation due to low fertility and emigration – but a combination of the two phenomena is mostly concentrated in eastern Europe, particularly in eastern Germany, Bulgaria and Ukraine. But the European population will also continue to age, and some demographers predict that babies born in the first decade of this century will live to an average age of 100.
And size is not always proportional to influence, if that’s really the concern at hand.
Since the late 19th century, when a massive decline in birth rates began in most of Europe, some demographers and long-forgotten futurologists have been busy envisioning an inevitable demise of Europe and “western civilisation”. However, it is not population size but affluence and technology that make some countries more powerful than others. Switzerland, with a population of 8 million, is globally more significant than, say, Bangladesh, with a population 20 times larger.