Rapid population growth “is almost certain to occur in countries least able to sustain it, and that will create a situation that will likely fuel instability and extremism,” warned CIA Director General Michael Hayden in a recent speech at Kansas State University, where he identified demographic change as one of the three global trends most likely to influence world events and challenge American security.

The UN mid-range world population projection for 2050 is 9.2 billion people, an approximately 40 percent increase over today’s population. This population growth, especially in developing and fragile states, may easily overwhelm state capacity. “When basic needs are not met,” explained Hayden, people “could easily be attracted to violence, civil unrest, and extremism.” Such civil unrest can spread across borders, destabilizing regions and impacting both developing and developed countries.

When their governments cannot meet their basic needs, people also often choose to emigrate. A dramatic influx of migrants—legal and illegal—from developing countries to developed ones poses significant challenges for the destination country, as governments must allocate resources for facilitating immigrant assimilation and, in some cases, countering extremism. Many European countries have struggled to integrate Muslim immigrants into their societies.

It’s interesting to note that the estimate of a 40 percent increase in population growth by 2050 is primarily based on the assumption that current levels of funding for family planning services will continue, which is far from certain. Promoting access to family planning has been a proven mechanism in reducing fertility. With growing populations threatening to overwhelm fragile states’ capacity and harm the environment, funding voluntary family planning programs could well be considered an investment in global security.