Barbara Hatch Rosenberg, a molecular biologist who spent decades pushing governments to take the threat of biological weapons seriously and who emerged as one of the most contentious voices in the FBI’s post-9/11 anthrax investigation, died on March 14, 2026. She was 97.
Dr. Rosenberg was a co-founder of the Scientists Working Group on Biological and Chemical Weapons at the Federation of American Scientists, a former adviser to the Clinton White House on bioweapons issues, and an early officer of ProMED-mail — the global electronic disease outbreak reporting system that became a foundational tool in modern public health surveillance.
From Cancer Research to Arms Control Advocacy
Born in New York City on June 26, 1928, Rosenberg trained as a biochemist, earning her bachelor’s degree from Cornell in 1950 and her Ph.D. in physical chemistry from Cornell in 1962. She built an early career as a cancer researcher at Memorial Sloan Kettering Cancer Center and as an associate professor at Cornell Medical College before pivoting to arms control issues, a shift shaped by her anti-Vietnam War activism in the 1960s and her participation in a 1986 Geneva conference aimed at strengthening the Biological Weapons Convention (BWC).
The BWC, signed in 1972, was the first multilateral treaty to ban an entire category of weapons of mass destruction — but it lacked a formal verification mechanism, a gap that Rosenberg and her colleagues spent years trying to close. As chair of the Scientists Working Group from 1991 to 2005, she produced dozens of technical reports supporting international BWC verification negotiations. She also advised the U.S. Congress Office of Technology Assessment on weapons of mass destruction in 1993–94, and in 1998 she was among a small panel of scientists who briefed President Clinton, the Secretary of Defense, and the Secretary of Health on biological weapons threats.
Her criticism of the George W. Bush administration’s 2001 rejection of a BWC verification protocol — published in an opinion essay in The Baltimore Sun just one week before the September 11 attacks — proved grimly prescient.
The Anthrax Investigation: Influence, Controversy, and a Wrong Turn
When anthrax-laced letters began arriving at news outlets and Senate offices in the fall of 2001, killing five people and sickening seventeen, Rosenberg quickly developed a theory: the culprit was an American government scientist or contractor, not a foreign terrorist. She was emphatic and public about this view, presenting her analysis at a Biological Weapons Convention meeting in Geneva in November 2001, briefing congressional staffers, and speaking with the FBI. Her argument drew both serious attention and sharp ridicule. But government scientists called her with tips, and the FBI repeatedly sought her out.
The controversy turned damaging when the FBI’s investigation focused on Dr. Steven J. Hatfill, a scientist who had worked at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) at Fort Detrick, Maryland. In a sworn deposition, FBI Special Agent Van Harp confirmed that Rosenberg had raised Hatfill’s name in a June 2002 meeting with the bureau and congressional staffers. Rosenberg maintained she had never explicitly named him. Hatfill was publicly declared a “person of interest” by Attorney General John Ashcroft in August 2002, subjected to intense media scrutiny, and ultimately exonerated. In 2008, he received a $5.8 million settlement from the Justice Department.
Rosenberg declined to apologize. The FBI eventually shifted its focus to Dr. Bruce Ivins, a USAMRIID scientist with actual access to the anthrax strain used in the attacks. Ivins died by suicide in July 2008, and Hatfill was officially cleared weeks later. Even then, Rosenberg continued to challenge the official narrative: a 2011 paper she co-authored raised the possibility that Ivins may have had help — or may have been innocent.
A Legacy Built on Early Warning
Whatever the complications of the anthrax episode, Rosenberg’s broader contributions to biosecurity endure. Her role in co-founding ProMED-mail in 1994 — initially launched under the National Academy of Sciences working group as a prototype rapid outbreak-reporting system — placed her among the architects of the global infectious disease early warning infrastructure that public health professionals rely on today.
Sources and further reading:
Barbara Hatch Rosenberg, Who Joined Hunt for Anthrax Culprit, Dies at 97 – The New York Times
Barbara Rosenberg – Co-Founder of Working Group, Emeritus Chair – Center for Arms Control and Non-Proliferation