I think the biggest cause for geopolitical instability is some sort of ecological disaster or global nuclear war and I think that's if anything more likely on a

I think the biggest cause for geopolitical instability is some sort of ecological disaster or global nuclear war and I think that's if anything more likely on a planet with large, young populations rather than smaller, older ones due to intensified resource or territorial competition. People have coined the term 'geriatric peace theory' for the effect that aging populations tend to be remarkably stable politically. Today if you think of who can wipe a few billion of the planet India and Pakistan come to mind, less so Germany or Japan.