The term BW is also used for toxins, non-living poisons of biological origin, which are either lethal like botulinum toxin or incapacitating like staphylococcus enterotoxin B. These four and about eight other agents were stockpiled for use as BW during the second world war and its aftermath. In the past two decades, the potential danger from BW has increased for two main reasons. First, the rapid progress of biotechnology and the advent of genetic manipulation have made it possible to produce many new agents. Second, as was emphasized by the Gulf War, BW are particularly attractive to some developing countries because they can be produced cheaply with relatively moderate facilities and be used in covert operations. The escalating dangers must be controlled.