The Blue Ribbon Study Panel on Biodefense held a meeting, Fighting the Next War: Defense Against Biological Weapons, on February 5, 2019, to get a better understanding of the responsibilities and requirements for federal biodefense efforts that are unique to the U.S. Department of Defense. We wanted to know more about the role of the Department in implementing the National Biodefense Strategy. Participants shared their experiences regarding the current threat environment, research and development programs, and the Department’s biodefense policies.