Project 638 was a covert operation conducted by the United States during the Cold War. Its primary goal was to develop and test various biological agents for potential use in warfare. The project aimed to explore the effectiveness of these agents against enemy forces. The project involved extensive research and experimentation, including the study of pathogens and toxins. It was part of a broader military strategy to enhance the U.S. defense capabilities. However, the ethical implications and potential risks associated with biological warfare led to significant controversy and scrutiny over such programs.