Just noticed this gem in the WMD Commission report RE: Libya’s BW program:
That being said, it should be noted that there are few distinguishing characteristics that enable the identification of chemical or biological facilities through imagery or other technical means. Moreover, much of the technology and expertise required for chemical and biological programs is dual-use, making it easier to acquire and more difficult for the Community to track. It is also apparent that, at least with regard to biological weapons, the relatively low volume of information could be attributed to the fact that Libya may not have actually had an active biological warfare program.
Note to Rumsfeld: absence of evidence is absence of evidence.