Keep in mind that as conditions worsen in any environment there comes a time when life cannot sustain itself. Russia loses the most population because conditions there are atrocious. Italy somewhat less, because conditions are somewhat better. But still there is an active incentive to not have children. There will come a time when governmental oppression in Britain will worsen to the point that British society will experience its own demographic collapse. Which will lead to conditions getting even worse, more governmental action to deal with the situation (the beatings will continue until morale improves), and accelerated population loss.
Societies do best when the members are left to take care of the small matters themselves. They die when their leaders try to do everything.
