FORBES | A new report issued by the Joint Monitoring Program on Water Supply and Sanitation shows that 2.1 billion people don’t even have access to safe drinking water at home. More than twice that number—4.5 billion people, or a full 60% of earth’s population—live without a toilet that safely protects them from human waste.

And, for the first time, the annual report provides global data on people’s access to hygiene. There the situation appears even more dire. In sub-Saharan Africa, only 15% of people are able to wash their hands with soap and water at home.

For generations, the United States has devoted a small portion of our national budget—currently less than 1 percent—to aiding the world’s least fortunate. And while this aid is certainly altruistic, it is not solely altruistic. It serves our national interest in a variety of ways. It promotes more resilient and prosperous economies, fosters more stable societies, and improves health and security worldwide.

I explore the issue and what we need today with Dr. Anand Parekh, Chief Medical Advisor of the Bipartisan Policy Center, Trustee of WaterAid America, and former Deputy Assistant Secretary for Health at the US Department of Health and Human Services. Read more at Forbes.