Gunnar Heinsohn "Sohne und Weltmacht: Terror im Aufstieg und Fall der Nationen"

I have recently read a review for this book written by a sociologist, economist and genocide researcher of the Bremen university. In his book he tells about the causes of waves of violence in third world countries, of frequent terrorist attacks and so on. His theory is, that if the percentage of the young men (15-29 year old) in the country is bigger than 30%, then there will be a risk of violent acts. He studied the demographic situation in Germany and in many countries nowadays. In Germany the proportion between 40-44 year old men and 15-29 old men is 100/50, whereas in Afganistan it is 100/403. Bigger number of young people creates tension, because young people are more energetic, they can act, protest against something. And it is a force, soldiers, who can fight real or imaginative enemies.
There are more interesting thoughts, examples and conclusions there. And I seem to agree with the writer's point of view.