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.  

There have long been disputes over the role of Congress and the president in waging military action.

China, India, and Pakistan have relatively small but growing nuclear arms programs. This nuclear competition is raising concern because of long-simmering tensions and a lack of efforts at minimizing …