evidence: The Trump Administration’s forays into academia, where the distinction between routine coöperation and impropriety can be nebulous, proved more troublesome than officials may have expected. The D.O.J. had been emboldened by the successful prosecution of more straightforward cases of industrial espionage. In 2013, Xu Yanjun, a senior operative in Jiangsu Province’s Ministry for State Security, reached out, under various aliases, to experts at American aerospace companies, offering them paid travel expenses and stipends to give presentations at Chinese universities. In 2017, he narrowed in on an employee at G.E. Aviation, seeking information related to composite fan blades used in jet engines, which the Chinese had been unable to replicate. The employee contacted the F.B.I., which instructed him to hand over dummy documents and eventually to arrange a meeting in Belgium, where Xu was arrested. For the Administration, such activity was only the most visible aspect of a more submerged menace. In 2018, Christopher Wray, the director of the F.B.I., testified before the Senate that China represented a "whole-of-society threat," and that its intelligence efforts were now exploiting "nontraditional collectors—especially in the academic setting, whether it’s professors, scientists, students."