ABD's ideology is not elaborated on in much detail, but the group advocates a return to a pre-industrial society. The group's more radical members believed that the human population had to be reduced to pre-industrial levels, an idea that would eventually motivate the Clade X attacks.
ABD was founded in the 1990's as an American think tank. At this time it was not violent or dangerous, and was most notable for lecture tours.
By the 2010's, a radical group had developed within the ABD, consisting of several scientists and centered around a charismatic leader (not named in the exercise). This group numbered around 30 people. They set up a lab in Zurich, Switzerland, where they worked on the Clade X virus. The lab was disguised as a small biotech company, allowing them to purchase the supplies they needed without raising suspicion.
By 2018, ABD had perfected the Clade X virus, a parainfluenza virus hybridized with the much more deadly Nipah virus. In April of that year, they released the virus in Frankfurt, Germany and Caracas, Venezuela. They would later conduct four more releases - one in Hong Kong, one in Kabul, one in Dubai, and one in Bethesda, Maryland. The Bethesda attack was specifically targeted at the National Institutes of Health, as the ABD hoped to cripple them in order to prevent them from stopping the disease's spread.
After Clade X had begun spreading around the world, ABD released a YouTube video claiming responsibility for the virus. A global manhunt quickly began, but the ABD's membership remained at large for months before they were finally arrested. The suspects were cooperative and gave their captors detailed outlines about the attacks, but did not or could not give information about how to create a vaccine. The nature and outcome of the legal proceedings against them are not known.
The pandemic continued for many months after the dissolution of the ABD, lasting well into the next year and possibly beyond that. By then it had killed 150 million people worldwide. It was projected that if no vaccine could be created, Clade X would kill 900 million people before burning out or becoming endemic.