Kenneth R. Weiss. July 22, 2012. Runaway population growth often fuels youth-driven uprisings. In fast-growing countries, many young men are unable to find employment or pay dowries. Frustrated ambitions can be an explosive force — and a reason for joining the Taliban. Los Angeles Times

In developing countries, runaway population growth has created vast ranks of restless young men with few prospects and little to lose. Their frustrated ambitions can be an explosive force, as shown by the youth-driven uprisings that toppled autocratic regimes in Egypt, Libya and Tunisia in 2011.

About 80% of the world’s civil conflicts since the 1970s have occurred in countries with young, fast-growing populations according to an analysis by the nonprofit Population Action International. A large youth population does not automatically result in violence. Religious and ethnic friction, political rivalries, economic disparities or food shortages can provide the spark. Mobs of unemployed young men provide the kindling.

In a sluggish agrarian economy, few young men can find legitimate employment. Their lack of a steady income essentially closes the door to marriage in a society where [in many countries] sex outside of wedlock is forbidden. Tradition requires paying a dowry and staging a wedding celebration, which together cost [many times the average annual household income].

Of the 2 billion or more people who will be added to the planet by 2050, 97% are expected to be born in Africa, Asia and Latin America, led by the poorest, most volatile countries.

“We are literally going to see 1 billion young people come into the populations in the arc of instability over the next two decades,” said Jack Goldstone, an expert on demography and revolutions at George Mason University in Virginia.

A youth boom contributed to the rise of the Nazis in 1930s Germany and to Japan’s military ambitions in the Pacific. And also the 1989 Tiananmen Square protests in China and the rioting in the U.S. in the 1960s and ’70s. [And according to Jared Diamond in “Collapse”, the genocide of the Tutsis by the Hutu was brought on by overpopulation, in areas where no Tutsis lived, Hutus slaughtered one another].

In 1974, U.S. national security advisor Henry Kissinger warned in a then-classified memo that the growing numbers of young people in the developing world were likely to be more “volatile, unstable, prone to extremes, alienation and violence than older populations. It is urgent that measures to reduce fertility be started.”

Yet for many years afterward, the growing ranks of youthful militants in distant lands were not widely seen as a major threat to America’s security. Until September 11, 2001.

The bipartisan commission that investigated the suicide hijackings, carried out by 19 young Arab men, said one factor in the rise of extremism in the Muslim world was “a large, steadily increasing population of young men without any reasonable expectation of suitable or steady employment — a sure prescription for social turbulence.”