Mystery Drones Swarmed a U.S. Military Base for 17 Days. The Pentagon Is Stumped.

U.S. Air Force Gen. Mark Kelly wasn’t sure what to make of reports that a suspicious fleet of unidentified aircraft had been flying over Langley Air Force Base on Virginia’s shoreline. Kelly, a decorated senior commander at the base, got on a squadron rooftop to see for himself. He joined a handful of other officers responsible for a clutch of the nation’s most advanced jet fighters, including F-22 Raptors. For several nights, military personnel had reported a mysterious breach of restricted airspace over a stretch of land that has one...