Current revolutions in biotechnology and neuroscience are changing military technologies, necessitating dramatic re-evaluations in arms regulatory regimes. This study assesses how these new technologies can be used in weapons systems - by governments and terrorists alike - and whether this frightening development can be brought under effective international control. Malcolm Dando begins by surveying the existing (and arguably inadequate) control mechanisms for chemical and biological weapons. He then discusses how earlier generations of toxin and bioregulatory weapons have been used by such states as Iraq, the Soviet Union and the USA, and explains, in non-technical terms, the implications for new weapons technology. Considering how international law might be applied to constrain undesirable military developments without restricting technological developments for peaceful purposes, Dando concludes with a proposal for an integrated control regime that would link international agreements, national legislation, and trade regulations.