Generally accepted facts about smallpox:
  1. Smallpox is highly contagious and could spread rapidly, killing millions
  2. Smallpox can be spread by casual contact with an infected person
  3. The death rate from smallpox is thought to be 30%.

1.  Smallpox is not highly contagioius
"The infection is spread by droplet contamination. Coughing and sneezing are not generally part of the infection. Smallpox will not spread like wildfire."  

Walter A. Orenstein, M.D., Director of the CDC's National Immunization Program (NIP), CDC meeting June 20, 2002

2.  Smallpox is spread by casual contact
"Transmission of smallpox occurs only after intense personal contact, defined by the CDC as constant exposure, occurring within 6-7 feet, for a minimum of 6-7 days." Am. J. Epid. 1971; 91:316-326.

Joel Kuritsky, MD, Director of the National Immunization Program and Early Smallpox Response and Planning at the CDC states:

3.  The deathrate from smallpox is 30%
Case fatality rate in adults was "much lower than  generally advertised" and closer to 10-15% in adults.  "Even without mass vaccination, smallpox would have died out anyway. It just would have taken longer."

Dr. Tom Mack, of USC, reported at the CDC meeting June 20, 2002 -The verbatim transcript of the Meeting of the Advisory Committee on Immunization Practices     (ACIP) June 19 and 20, 2002 ;
In 1900, 21,064 smallpox cases were reported, and 894 patients died…that is 4.2%
MMWR.  Achievements in Public Health, 1900-1999 Impact of Vaccines Universally Recommended for Children -- United States, 1990-1998 . April 02, 1999/48(12);243-248

The Defense Advanced Research Projects Agency (DARPA) lists 65 known biological warfare agents and an infinite number of organisms that can be created through genetic engineering.

If we vaccinate against smallpox [and anthrax], an enemy could easily pick a different microorganism for use.

Mack TM.  Smallpox in Europe, 1950-1971. J Infect Dis. 1972 Feb;125(2):161-9. No abstract available. PMID: 5007552 [PubMed - indexed for MEDLINE]
Abstract:  "The 49 importations of smallpox into western countries in the past 20 years are reviewed.  Such importations have been caused, for the most part, by visiting foreigners or by returning nationals who had scars from childhood vaccination.  When appreciable numbers of indigenous cases or deaths have resulted, spread in hospitals have been responsible.  Most deaths have been among medical personnel or elderly patients.  The reputation of smallpox as a catastrophic, unpredictable, and entirely uncontrollable disease seems unwarranted under modern conditions.  Fear of incidents such as these should not be used to justify a policy of universal vaccination of children."