Sub-Saharan Africa is home to many of the world’s longest-ruling heads of state. Pro-democracy advocates have at times successfully stopped presidents from extending their mandates, but the authorita…

The United States continues to seek strategies for responding to the growing number of migrants fleeing poverty, violence, and other challenges in the Central American region.

The sprawling U.S. water system is central to the nation’s economy, but chronic underinvestment, increasing demand, and the consequences of climate change have revealed the system’s weaknesses.  

The Zika virus, which has been found to cause severe birth defects, has spread across the Americas, prompting the World Health Organization to declare a global health emergency.