It is nearly 15 years since biological weapons (BW) have become a signifi cant national security preoccupation. This occurred primarily due to four circumstances, all of which occurred within a short span of years. The fi rst, beginning around 1990 and repeated many times in the years that followed, was the offi cial U.S. Government suggestion that proliferation of offensive BW programs among states and even "nonstate actors"-terrorist groups-was an increasing trend. The second was the discovery, between 1989 and 1992, that the Union of Soviet Socialist Republics (USSR) had violated the Biological Weapons Convention (BWC) since its ratifi cation in 1975 and had built a massive covert biological weapons program, the largest the world had ever seen. The third was the corroboration by the United Nations Special Commission (UNSCOM) in 1995 that Iraq had maintained a covert biological weapons program since 1974, and had produced and stockpiled large quantities of agents and delivery systems between 1988 and 1991.