Youth Explosion in the Developing World
This surge of adolescents virtually guarantees that the number of schooled youth will outpace job growth, leaving even educated young men underemployed, frustrated, and resentful of those who enjoy the opportunities they lack. While not the overt cause of armed conflict, these demographic factors can facilitate recruitment into insurgent organizations and extremist networks or into militias and political gangs— now among the major employers of young men and the main avenues of political mobility in weaker countries.
Comparisons of data on population and warfare reveal that countries where young adults make up more than 40 percent of the working-age population are nearly 2.5 times more likely to experience a new outbreak of armed civil conflict than countries with lower proportions of young adults. And because a youth bulge usually occurs in rapidly growing populations where fertility is high, where women have low status, and where vital services are limited, a youthful demographic is often accompanied by other potentially destabilizing demographic forces and adverse social and economic conditions. For example, nearly all of the countries with a large youth bulge are also undergoing a rapid rate of urban growth (more than 3 percent per year), contributing to urban decay and sprawling slums.
In other words, these populations are breeding grounds for terrorists cells and criminal gangs. However, the developed world has an opportunity to help these countries stabilize their populations -- and ultimately lower the global threat of crime and terrorism -- through economic investment, promotion of family planning, and helping to expand women's roles in government and business.
UPDATE: Meanwhile, Japan is experiencing a "baby bust." A declining birthrate, combined with dramatically longer lifespans, means that schools are being converted into senior centers, and obstetricians are in short supply. The increase of women in the workforce, more people choosing not to marry, and a generally high cost of living are cited as the key reasons behind Japan's low birthrate.