Bioweapons programs in the Soviet Union and the U.S. flourished in the anxious climate of the Cold War. (Above is a scene from one of the U.S. Army labs at Fort Detrick, Maryland.) Both nations explored the use of dozens of different bacteria, viruses, and other biological toxins. They also devised sophisticated ways to disperse these agents in fine-mist aerosols, to package them in bombs, and to launch them on missiles.
In 1969, the U.S. military conducted a massive field test in the Pacific. The war game—involving a fleet of ships, caged animals, and the release of lethal agents—proved the effectiveness of the U.S. bioweapons. Little did the U.S. team know, however, that Soviet spies were in nearby waters, collecting samples of the agents tested.
At the end of 1969, President Richard Nixon terminated the offensive biological warfare program and ordered all stockpiled weapons destroyed. His decision hinged on a calculation that continuing an offensive program encouraged other nations to do the same, and was therefore, on balance, a security risk. From this point on, U.S. researchers switched their focus to defensive measures, such as developing "air-sniffing" detectors.
In 1972, the U.S. and more than 100 nations signed the Biological and Toxin Weapons Convention, the world's first treaty banning an entire class of weapons. The treaty barred possession of deadly biological agents except for defensive research. Yet no clear mechanisms to enforce the treaty existed. Just as it signed the treaty, the Soviet Union fired up its offensive program.