Following the September 11 , 2001 attacks on the U.S. cities of New York City and Washington , D.C. , the organization Al-Qaeda responsible for the attacks announced that they were attempting to acquire radiological , biological , and chemical weapons . This threat was lent a great deal of credibility when a large archive of videotapes was obtained by the cable television network CNN in August 2002 showing , among other things , the killing of three dogs by an apparent nerve agent
September 11 , 2001 attacks
September 11 attacks
Chemical warfare