By Richard Cincotta – Young and war-torn countries have been the ones most at risk for violent societal conflict until recently. From the 1970s through the 1990s, more than 90 percent of all societal conflicts broke out in countries with a youthful age structure-a population with a median age of 25 years or less. And wherever civil and ethnic wars emerged, they tended to persist. The average societal conflict that began between 1970 and 1999 averaged about 25 battle-associated fatalities per year for about six years. Some-including the Angolan Civil War, Northern Ireland’s “Troubles,” Peru’s war against the Shining Path, and the Afghan Civil War-endured for two decades or longer. In contrast, inter-state conflicts that began between 1970 and 1999 lasted, on average, less than two years (see UCDP/PRIO Conflict Database).
This simple characterization worked well until the first decade of the 21st century. The proportion of youthful countries experiencing one or more violent intrastate conflicts declined from 25 percent in 1995 to 15 percent in 2005.
What is behind this encouraging slump in political unrest?
One hypothesis is that peace support operations (PSOs)-peacekeepers, police units, and specialized observers that are led, authorized, or endorsed by the United Nations-made a difference. The expansion in the size and number of PSOs that were deployed in the aftermath of societal conflict, beginning in the early1990s, appears to have dampened the persistence of some conflicts, and prevented the reemergence of others. Whereas PSOs only rarely were deployed in the wake of societal conflict before the 1990s, from 1990 to 2009, 47 PSOs were deployed in these circumstances. In addition, those more recent deployments were to the two most youthful regions: sub-Saharan Africa (39 PSOs in 12 countries); and the East Asian Pacific Islands (eight PSOs in three countries).
According to William Durch and Tobias Berkman, this upsurge of PSOs in the aftermath of societal warfare was less a change of heart or modification of a global security strategy, and more an outcome of the unraveling of the web of Cold War international relations. Before the 1990s, the majority of PSOs were United Nations-led operations that were mandated to monitor or help maintain cease-fires along mutual frontiers. Because insurgents were typically aligned with either the Soviets or a Western power, Security Council authorization to mediate a societal conflict was difficult to secure.
This changed with the breakup of the Soviet Union and the initiation of PSOs by regional organizations, including operations by the Economic Community of West African States (ECOWAS) in Liberia and Sierra Leone and an operation by the Commonwealth of Independent State (CIS) in Tajikistan during the 1990s, the NATO-led Kosovo Force in 1998-99, and the Australian-led Regional Assistance Mission to the Solomon Islands beginning in 2003. Between 1985 and 2005, the number of PSOs that were deployed in the wake of societal conflict increased from two to 22. In contrast, those led, authorized, or endorsed by the UN to maintain cease-fire agreements between neighboring states rose from three to four. By 2009, nearly 100,000 peacekeepers were stationed in countries that had recently experienced a societal conflict and of those, about 70 percent had youthful populations (see figure below).
What do country demographic trends suggest for the demand for PSOs over the next two decades?
For societal conflict, political demographers foresee the demand for PSOs continuing to decline among states in Latin America and the Caribbean-with the exception of sustained risk in Guatemala, Haiti, Bolivia, and Paraguay-and across continental East Asia. Gauged by age-structure alone, the risk of societal warfare is projected to remain high over the coming two decades in the western, central, and eastern portions of sub-Saharan Africa, in parts of the Middle East and South Asia, and in several Asian-Pacific Island hotspots-Timor Leste, Papua New Guinea, Philippines, and Solomon Islands.
But even in some countries that are losing their age-structurally youthful blush, domestic political relations could turn out less rosy than this simple age-structural model forecasts. In other words, there are roadblocks to a “demographic peace.” Among them is an increasing propensity for a specific demographic configuration of ethnic conflict: warfare between state forces and organizations that recruit from a minority that is age-structurally more youthful than the majority or plurality ethnic group-such as conflicts that feature the Kurds in Turkey, the Shiites in Lebanon, the Pattani Muslims in southern Thailand, and the Chechens of southern Russia. However, this twist on the “youth bulge model” is difficult to unpack. Suffice it to say that, when political demographers look over the United Nations Population Division’s current demographic projections, they see nothing to indicate either the waning of societal warfare, or the withering of demand for PSOs, on the horizon.
 Cincotta, R.P. and E. Leahy. 2006/2007. “Population Age Structure and the Risk of Civil Conflict: a
Metric.” Environment Change & Security Project Report, 12: 55-58. Also at: http://www.wilsoncenter.org/topics/pubs/PopAgeStructures&CivilConflict12.pdf; societal conflicts are by definition intra-state.
 Source for demographic data in this article is: United Nations Population Division. 2009. Population Prospect, the 2008 Revision. New York: United Nations.
 Durch, W.J. and T.C. Berkman. 2006. Who Should Keep the Peace? Providing Security for Twenty-First-Century Peace Operations. Washington, DC: Stimson Center. http://www.stimson.org/books-reports/who-should-keep-the-peace/