The authoritative guide to ensuring science and technology make life on Earth better, not worse.

Watch the 2025 Doomsday Clock announcement on January 28


Jonathan B. Tucker

Tucker manages the Biosecurity Education Project at the Federation of American Scientists (FAS). Trained in biology and security studies, he is an expert on biological and chemical arms control, bioterrorism, and emerging biological threats. Prior to his position at FAS, he was the founding director of the Chemical and Biological Weapons Nonproliferation Program at the James Martin Center for Nonproliferation Studies (CNS). Before joining CNS in 1996, Tucker worked for the congressional Office of Technology Assessment and the US Arms Control and Disarmament Agency; in February 1995, he was a UN biological weapons inspector in Iraq. He has written or edited four books on biological and chemical weapons, including War of Nerves: Chemical Warfare from World War I to Al Qaeda.