1972: The Biological Weapons Convention is established. The treaty prohibits the research, development and production of offensive biological weapons. The treaty does allow defensive work in the area of biological weapons. The Soviet Union and the United States both ratify the pact.
1979: An unusual anthrax outbreak in the Soviet city of Sverdlovsk kills at least 64 people. The Soviet government blames the outbreak on contaminated meat, but there is suspicion within the international scientific and intelligence communities that the Sverdlovsk outbreak was caused by an accidental release of anthrax spores from a nearby suspected biological weapons facility. All evidence available to the U.S. government indicates a massive release of aerosolized B. anthracis spores. In 1992, Russian President Boris Yeltsin acknowledges that the incident was indeed related to the microbiology facility.
1980-88: Chemical weapons are used extensively during the Iran-Iraq war, mainly by Iraq. After the Gulf War, in 1991, the United Nations Security Council orders Iraq to halt its biological, chemical and nuclear weapons programs. The U.N. Special Commission (UNSCOM) begins post-war inspections that have continued with numerous interruptions and obstacles thrown up by Iraq.
1995: Members of the Aum Shinrikyo religious sect release sarin gas in the Tokyo subway system, killing 12 commuters and injuring more than 5,000. Due to the poor quality of the sarin agent and an ineffective dispersal system, casualties are lower than expected. Afterward, the religious group is found to have been experimenting with anthrax and other biological agents.
1998: The U.S. Defense Department begins an anthrax vaccination program to immunize all military personnel against anthrax.