Former UN chief weapons inspector Hans Blix was interviewed by CNN war correspondent Christiane Amanpour on March 17, 2004. “The primary difficulty with looking for weapons of mass destruction in Iraq, said Blix, was the ‘problem of proving the negative. For example, how can you prove that there is not a tennis ball in this room? Or that there is no anthrax in all of Iraq?’ The United States and the United Kingdom wanted black-and-white answers, and instead they got ‘lots of shades of gray in the reports.’ ”
– Bonnie Azab Powell, “U.N. Weapons Inspector Hans Blix Faults Bush Administration for Lack of ‘Critical Thinking’ in Iraq,” U.C. Berkeley News, March 18, 2004