Some of these nations are believed to sponsor terrorism and have demonstrated a willingness to act aggressively against their perceived enemies. About 25 nations have BCWs or could produce them. That's three times the number of nuclear powers. And their ranks include countries that are small and large, rich and poor, respected and rogue. CWs were, however, used in the Iran-Iraq war during the 1980s, and the Iraqis had manufactured large quantities that were available, although not used, during the gulf war.
Biological weapons are pound for pound the most potent weapons that exist.
Certainly the cost of producing BCWs is far less substantial than the cost of producing nuclear weapons. Preventing the production, distribution, and eventually the use of at least some types of BCWs poses an extremely difficult challenge. Efforts to prevent proliferation may slow these developments but seem unlikely to prevent them. Dangers do exist in the BCWs production process, and delivery of such weapons is also difficult. But these dangers and difficulties seem likely to be overcome.