TOPOFF is the acronym for "Top Officials". According to the July 24, 2002, U.S. Department of State's Office of Counterterrorism Fact Sheet "TOPOFF (Top Officials)":
- "The U.S. Congress, responding to terrorist events such as the 1995 Tokyo subway sarin gas attack, concluded in 1998 that America's top government officials should receive better training to respond to a complex attack involving Weapons of Mass Destruction (WMD). To address this challenge, Congress mandated the Department of State and Department of Justice to conduct a series of challenging, role-playing exercises involving the senior federal, state, and local officials who would direct crisis management and consequence management response to an actual WMD attack. The result was TOPOFF (Top Officials), a national-level domestic and international exercise series designed to produce a more effective, coordinated, global response to WMD terrorism."
This exercise, however, was not the first involving ANSER Institute staffers. Writing for Biodefense Quarterly in September 2000, Dr. Inglesby, Rita Grossman, and Dr. O'Toole of the ANSER Institute wrote "A Plague on Your City: Observations from TOPOFF." TOPOFF was the code name for a Defense Department nationwide counterterrorism exercise.