THE CONDITIONS REQUIRED FOR THE CONSTRUCTION OF A NUCLEAR DEVICE ARE DESCRIBED, AND THE RESOURCES NEEDED FOR ARMING AND FIRING A STOLEN NUCLEAR DEVICE ARE INDICATED. IN THE EXAMINATION OF TOXIC CHEMICAL AGENTS CAPABLE OF MASS DESTRUCTION, THE TOXIC PROPERTIES, PREPARATION, AND USES OF ORGANOPHOSPHORUS COMPOUNDS, FLUOROACETATES, AND OTHER FLUORINATED HYDROCARBONS ARE EXAMINED. THE TOXIC PROPERTIES, PREPARATION, AND USES OF BOTULINUM TOXIN AND ANTHRAX BACILLI ARE DISCUSSED AS BIOLOGICAL AGENTS OF DESTRUCTION. THE DISPERSAL OF THE MENTIONED TOXIC AGENTS IS ALSO CONSIDERED. THE PLUTONIUM DISPERSAL WEAPON IS EXPLORED AS A SPECIAL CASE. THE POTENTIAL TERRORIST MASS DESTRUCTION THREAT REQUIRES VARIOUS LEVELS OF TECHNOLOGICAL SKILLS, DEPENDING ON THE NATURE OF THE THREAT. A CREDIBLE THREAT INVOLVING A DISCRIMINATE NUCLEAR DEVICE WOULD REQUIRE THE GREATEST SKILLS, WHILE CONSIDERABLY LESS SKILL WOULD BE REQUIRED TO PRECIPITATE A CLANDESTINE NUCLEAR THREAT WITH A DEVICE OF UNCERTAIN YIELD AND WITH SOME UNKNOWN PROBABILITY OF FUNCTIONING IN THE NUCLEAR MODE. FEWER SKILLS WOULD BE NEEDED TO DEVELOP A CREDIBLE MASS DESTRUCTION THREAT WITH EITHER A CHEMICAL OR BIOLOGICAL AGENT. TO DATE, SUCH SKILLS ARE BEYOND THE CAPABILITIES OF CONTEMPORARY TERRORIST ORGANIZATIONS. IN ADDITION TO THE TECHNOLOGICAL AND PROCEDURAL REQUIREMENTS THAT MUST BE CONFRONTED, TERRORISTS CONSIDERING MASS DESTRUCTION PLANS MUST ALSO CONSIDER POLITICAL AND SELF-INTEREST FACTORS LIKELY TO BE INVOLVED IN REACTION TO AN ACT OF MASS DESTRUCTION. WHILE TERRORIST ACTIVITY MAY APPEAR IRRATIONAL TO OBSERVERS IN WESTERN INDUSTRIAL SOCIETIES, TERRORISM CAN BE, AND USUALLY IS, FROM THE PERSPECTIVE OF ITS PERPETRATORS, A RATIONAL ATTEMPT TO ACHIEVE AN ORGANIZATIONAL GOAL THAT CANNOT BE ACCOMPLISHED THROUGH TRADITIONAL DISPLAYS OF POWER USED BY ESTABLISHED NATIONS: THEREFORE, IN CONSIDERING THE USE OF WEAPONS OF MASS DESTRUCTION, MOST, IF NOT ALL, KNOWN TERRORIST GROUPS WOULD CONSIDER THE CONSEQUENCES TO THEIR ULTIMATE GOALS OF SUCH A DEED. REACTIONS TO A CATASTROPHIC DEATH EVENT COULD ONLY BE DISASTROUS TO ANY LONG-TERM POLITICAL GOALS OF A TERRORIST GROUP. A MANIACAL GROUP OF INDIVIDUALS DRIVEN BY A THOROUGHLY IRRATIONAL HATRED THAT SEEKS DESTRUCTION AS AN END IN ITSELF WOULD MOST LIKELY BE PSYCHOLOGICALLY INCAPABLE OF THE CAREFUL AND RATIONAL PLANNING NEEDED TO ACCOMPLISH A DEED OF MASS DESTRUCTION. (RCB)