The U.S. military has quietly developed and deployed a new operational capability in the Indo-Pacific region to detect and track hypersonic weapons, repurposing existing sensors and command and control systems to display tracks of ultra-fast maneuvering vehicles -- such as those being fielded in increasing numbers by China -- in a development that sheds new light on Pentagon efforts to improve missile warning and missile defense missions. The previously unreported capability, called Defense Against Hypersonic Weapons in the Pacific, has...