It wasn't that long ago when scientific collaboration between the United States and China was enthusiastically encouraged as a means to accomplish the best science. American universities established campuses in China, set up exchange programs for students and trainees, and hired highly productive Chinese researchers. That all changed in 2018, when then-President Trump launched the China Initiative to rid US academia of Chinese spies. As reporter Jeffrey Mervis describes in this issue of Science, the National Institutes of Health (NIH)-the largest federal funder of biomedical research-vigorously responded to this charge. The agency's allegations and investigations have not only destroyed careers but also eroded trust in the agency and federal government across the scientific community.