I assume this is what they're talking about: "Under the Defense Authorization Act, the President is authorized to waive the Federal Food, Drug, and Cosmetic Act's (the act) informed consent requirements in military operations if the President finds that obtaining consent is infeasible or contrary to the best interests of recipients and on an additional ground that obtaining consent is contrary to national security interests."

https://www.fda.gov/science-research/clinical-trials-and-human-subject-protection/protection-human-subjects-informed-consent-exception-general-requirements#:~:text=Under%20the%20Defense%20Authorization%20Act,on%20an%20additional%20ground%20that