1) demographics are collapsing worse than expected for high value cohorts (working and fighting age men and child bearing women) because older numbers didn’t cohort ages eg real numbers can linearly decline supported but large older cohorts while younger cohorts can collapse much faster.
2) The UN failed to do math in the cohort trap (each generation of women is smaller making less children) that bends down the curve even more steeply faster
3) china is undergoing strategic compression and Russia is already in it. Russia seeks to have chosen to “go out in a flame rather than slowly decline”
4) the third and developing world was widely assumed to be our demographic bailout, latest numbers show they are collapsing faster than the developed non Asian world.