It's almost inevitable with ongoing peace populations will stabilize but to what level?
The demographic pyramid will be a demographic condom, and this doesn't bode well for progress. The people driving society will be old and this is a dangerous mix not for conflict or war but for stagnation. It's no suprise Japan shifted heavily to the regressive in the last 30 years and it won't be a surprise if Europe does in the next 30. What happens when the political apparatus of democracy facilities only regressive forces within the society. I think democracy is great but if there is a weakness in this organization method, is that it's largely demographics driven.
England is a good example I think of a very regressive shift to the right, the demographics lends itself to the Tories win elections for the 30-40 years straight. Corbyn winning the election is kind of like the Labour party entering a hospice. How can a Labour party win if the demographic is retiring or retired? And I don't see Corbyn with enough support to progress, more a ethical progressive but isolationist, and only token measures for material progress(because the people voting will not support them). I don't see him having the influence or power and mainstream support to stop the class war going in England.