On a clear, crisp morning, the peace and security of the United States was forever shattered by four hijackings on 11 September 2001 (henceforth, 9/11) that resulted in the collapse of the World Trade Center (WTC) towers, the destruction of a section of the Pentagon, and the passenger-induced plane crash on a rural Pennsylvania field. Within a mere 90 minutes, the potential threat of terrorism and the vulnerabilities of America became understood by a traumatized public. In today's technology-based society, an everyday object could be transformed into a weapon of mass destruction (WMD). Apparently, al-Qaida terrorists surpassed their wildest dreams of robbing Americans of their serenity and security. Their heinous attack captured headlines for months and will continue to do so for years to come. By broadcasting much of the disaster live, including the toppling of the north and south WTC towers, the media unwittingly assisted in magnifying the potential risks that modern-day terrorism poses. This heightened state of anxiety probably induced the anthrax terrorist to capitalize on the insecurity and hysteria that had already gripped the nation. That is, the mailing of anthrax letters was a complementary incident to the 9/11 hijackings, thereby allowing the two incidents to have a greater influence than either would have had on its own. Although those responsible for the two sets of events surely differed, the timing of the anthrax letters was not coincidental.

The events of 9/11 marked the largest ever terror attack on US soil – or anywhere – and resulted in the death of just over 3,000 people.