Dozens of countries around the world have suffered civil conflicts in the past few decades, with the highest concentration in Sub-Saharan Africa. The direct humanitarian consequences of war for survivors are enormous in physical insecurity, loss of property, and psychological trauma. There may also be lasting economic development costs for societies that experience violent civil conflicts. And the international “spillover” effects of conflicts can be large for neighboring countries faced with refugee flows, lawlessness on their borders, and the illicit trades in drugs, arms, and minerals that proliferate in conflict zones. This insecurity has foreign policy implications for the United States along multiple dimensions.

But what causes this insecurity and what can be done about it? In this chapter, I first describe recent academic research that finds a strong link leading from poverty to violence in less developed countries. I then lay out some of the implications of this core finding for public policy and in particular for the design of foreign aid.