A global surge in avian flu outbreaks in birds and some mammals is worrying poultry farmers, scientists, and health experts. The trend is provoking questions about the future of the disease and globa…

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 United States’ withdrawal from the arms control agreement has heightened tensions and left the remaining signatories scrambling to keep the deal alive.