The Chengdu J-20 made its maiden flight on January 11, 2011, deliberately timed to coincide with U.S. Defense Secretary Robert Gates’ meeting with Chinese President Hu Jintao in Beijing that same morning. The flight was a diplomatic message. What the West did not know was how much of the aircraft had been stolen — from Lockheed Martin’s F-35 program, from Boeing’s F-22 files, from the wreckage of an F-117 shot down over Serbia, and from Russia’s…