The connections between security and demographic trends-including migration patterns, age distribution, and population growth rates-have become increasingly prominent in academic and policy circles, as well as in the mainstream media. While researchers have been studying these links for decades, they are worth a deeper look-not only because of their newfound attention, but also because we now have more evidence to evaluate them.

No reasonable scholar or practitioner would argue that there is a simple causal relationship between demography and security-i.e., that a total fertility rate of 5.0 children per woman indicates that civil war will break out 20 years from now, or that a country cannot remain stable unless its age distribution resembles a bell curve. However, many argue that demographic trends can interact with other factors such as poverty, poor governance, competition for natural resources, and environmental degradation to exacerbate tensions and contribute to conflict. All of these factors influence each other-for example, high population density can accelerate environmental degradation, or poor governance can lead to inequitable access to natural resources.

The "Youth Bulge"

Perhaps no demographic phenomenon has received as much attention over the past few years as the "youth bulge." A youth bulge happens when a country's population has a disproportionately large number of young people (typically between 15 and 29 years of age). When this demographic profile is viewed as a population pyramid, the bottom-the youthful population-"bulges" out. These population pyramids of Afghanistan, Angola, and the Occupied Palestinian Territories offer classic examples of youth bulges.

Many experts argue that when a country has a large number of youth with limited opportunities for work, these young people are more likely to engage in violence. The situation is worsened if young men also face poor marriage prospects, which can happen if there are more men than women in their age cohort; if they lack the "means" to be considered eligible for marriage, such as land or cattle; or if women traditionally marry older men in their culture. The Economist recently argued that youth bulges are one cause of recent violence in Gaza and Kenya. A related-but more controversial-argument is that differential population growth among different ethnic groups within a country (both overall and among youth) can contribute to conflict.

On the Other Hand

But demography is not destiny, and family planning and reproductive health can play an important role in preventing and reducing instability. If family planning is available and affordable, women and couples generally choose to have fewer children, a quality seen across time, countries, and cultures. When a country with a youth bulge makes family planning available to its population, the attendant decrease in population growth moves a country along the demographic transition from high birth and death rates to low birth and death rates. Over time, the youth bulge generation will become a society's working members, providing for their parents and children. If a country is able to make this transition peacefully, the country enjoys a "demographic dividend," also known as a "demographic bonus."

Demographic dividends such as the ones achieved by the "Asian Tigers" (Hong Kong, Singapore, South Korea, and Taiwan) are made possible not just by family planning, but also by other variables, including education (especially for girls), good governance, and employment opportunities. The World Bank's 2007 World Development Report: Development and the Next Generation detailed the actions a country should take to harness the power of the demographic dividend and avoid potential pitfalls. It also noted that a large number of countries, particularly in Africa, will be facing this situation in the coming decades. Family planning will not end conflict, of course, but slowing the rate of population growth can help stabilize a country in turmoil.

Isn't the World Losing People?

When discussing population and family planning, the first question I here is often, "Isn't the world losing people?" The popular press focuses on several countries (including Japan, Russia, and much of Western Europe) that have fallen below "replacement fertility," the number of children per woman (2.1) at which population neither increases or decreases. Fertility in the United States is almost exactly 2.1, but the population is growing rapidly due to immigration. The media's focus on global aging makes sense: Aging (and especially shrinking) countries therefore have higher dependency ratios (the ratio of dependent youth and seniors to the working age population) find it difficult to pay for social security and other programs for the elderly, and economic growth is difficult to sustain.

The worldwide trend is much different. Presently, the world is adding nearly 75 million people to its current 6.5 billion residents every year. World population projections estimate that the world will grow to between 7.3 and 11.2 billion people by 2050. Ninety-nine percent of this projected population growth will occur in the developing world. Why is there such a huge variation in the population projections? Some of it has to do with assumptions about disease, urbanization, and other factors. But much of it concerns the world's commitment to family planning. The United Nations' mid-level population projection, for example, assumes that funding for family planning programs in the developing world will increase in the future. This is not currently happening, thus making it more likely that the UN mid-level estimate will be exceeded.

Some military strategists in countries with declining birth rates are concerned about future troop levels. Additionally, the fears of declining birth rates in some countries are often exacerbated by nativist sentiments that limit immigration. Such 'security' concerns could be used by some to justify pro-natal policies, but from a global perspective, this would only add to the problem of growing world population."

Family Planning for Family Planning's Sake

Even though family planning can reduce strains on a society and help avoid conflict, these are merely added benefits of reproductive health services, not reasons for supporting them. Deciding how many children to have is one of the most important decisions a woman or a couple can make, and providing women and couples with accurate information and affordable family planning options empowers them to decide the size and timing of their family. To that end, policymakers should not set "goals" for fertility rates or employ coercive methods. They should focus efforts on meeting the unmet need for modern contraceptives.

Family planning is an issue of human rights. All the other benefits of family planning-improved maternal and child health, better education, more investment of resources in each child, and reduced risk of conflict-are icing on the cake.