Chinese Spy Wanted GE’s Secrets, But the US Got China’s Instead

In January 2014, Arthur Gau, an aerospace engineer who was nearing retirement age, received an unexpected email from a long-lost acquaintance in China. Years before, Gau had made a series of trips from his home in Phoenix to speak at the Nanjing University of Aeronautics and Astronautics, or NUAA, one of China’s most prestigious research institutions. The original invitation had come from the head of a lab there studying helicopter design.

Increasingly, however, Gau had heard from someone else, a man who worked at the university in a vague administrative capacity. Little Zha, as the man called himself, was the ...