"This monograph is comprised of six substantive sections. An opening introductory section sets the global context in which the threat of 'bioterrorism' should be placed. It briefly surveys other nonmilitary challenges to national and global security that the United States and other nations currently face, and will face in the coming decades. It does so, where possible, by including the mortality levels currently resulting from these factors, particularly natural disease agents, and the levels that can be projected for them. This provides a comparative framework within which bioterrorism can more properly be assessed. The second section, using U.S. Government sources, surveys the evolution of offensive state biological weapons programs. This demonstrates that official estimates of the number of such programs have diminished by between one-fourth and one-third, from a peak of some 13 nations in mid-2001. What is known regarding any proliferation from these programs is also surveyed, as well as state assistance to nonstate actors. The third section surveys the evolution of the efforts by nonstate actors--terrorist groups--to obtain, develop, and use biological agents. The survey covers the entire 20th century, and up to the present day, focusing on the last 25 years."