Russia has a very high rate of population decline, the country is losing close to 1 million people every year. According to the UN and other official bodies, Russia's population (currently at around 140 million) will fall under 100 million by the middle of this century, and could fall as low as 60 million by the end of this century.
This would be a tremendous problem for any country, but Russia is not just any country, it's a gigantic country, which will cause problems of a specific type.
Most of the remaining Russians will be living in the European part of Russia, leaving two thirds of the country virtually empty. We can wonder if Russia will be able to maintain its territorial control over most of Siberia, especially with a southern neighbor like China, which by the end of the century will have become a superpower with close to 2 billion people, the empty lands of Siberia with their natural resources will look very tempting for an ever growing China.
Here's a page on
Wikipedia and another page on the
Population Reference Bureau about Russia's population decline.
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