Chenguang Gong, a 59-year-old dual citizen of the U.S. and China, has pleaded guilty to stealing more than 3,600 trade secret files from a tech company based in Southern California. The stolen materials included highly sensitive blueprints for advanced infrared sensors integral to U.S. missile detection and defense systems—technology used on fighter jets and space-based platforms. Officials say the breach may have compromised key aspects of national security.