In the 1970s, at the height of the Cold War, American military planners began to worry about the threat to U.S. warplanes posed by new, radar-guided missile defenses in the Soviet Union and other nations. In response, engineers at places like U.S. defense giant Lockheed Martin’s famous Skunk Works stepped up work on stealth technology that could shield aircraft from the prying eyes of enemy radar. This advantage is now under threat. In November 2018, China Electronics Technology Group Corporation (CETC), China’s biggest defense electronics company, unveiled a prototype radar that it claims can detect stealth aircraft in flight. The radar uses some of the exotic phenomena of quantum physics to help reveal planes’ locations. It’s just one of several quantum-inspired technologies that could change the face of warfare. The pursuit of these technologies is triggering a new arms race between the US and China, which sees the emerging quantum era as a once-in-a-lifetime opportunity to gain the edge over its rival in military tech.