Leaders at the top of al Qaeda's hierarchy, the evidence shows, completed plans and obtained the materials required to manufacture two biological toxins - botulinum and salmonella - and the chemical poison cyanide.
Governors normally have jurisdiction over public health emergencies, but a widespread biological attack would cross state boundaries.
U.S. surveillance of Pakistan extends far beyond its nuclear program. There are several references in the black budget to expanding U.S. scrutiny of chemical and biological laboratories.
In the field of biological weapons, there is almost no prospect of detecting a pathogen until it has been used in an attack.