THE AVAILABILITY OF FISSIONABLE MATERIALS, NUCLEAR POWER PLANTS, NUCLEAR WASTE STORAGE FACILITIES, AND TECHNOLOGICAL INFORMATION MAKE THE CHANCE OF A NUCLEAR THREAT BY TERRORISTS POSSIBLE. TERRORISTS MIGHT DEVELOP NUCLEAR WEAPONS THEMSELVES OR SABOTAGE NUCLEAR PLANT FACILITIES. THERE WERE AT LEAST 175 INSTANCES OF VIOLENCE OR THREATS OF VIOLENCE AGAINST U.S. NUCLEAR FACILITIES FROM 1969-1977. INTRINSIC BEHAVIORAL FEATURES OF TERRORIST GROUPS WHICH INCREASE THE NUCLEAR WEAPONS THREAT ARE DISCUSSED. THE GROUPS EXHIBIT AN ORIENTATION TO VIOLENCE WHICH DOES NOT OPERATE ACCORDING TO THE TRADITIONAL CODE OF HONOR IN WARTIME--SELECTING RANDOM TARGETS ON A WORLDWIDE BASIS, A RELATIVE INSENSITIVITY TO RETALIATORY THREATS, AND A TREND TOWARD GROUP COOPERATION. IT IS STATED THAT MUCH OF THE WORLD TOLERATES OR SUPPORTS TERRORIST ACTIVITY, AND THIS IS EXPLAINABLE IN TERMS OF TWO DIFFERENT TYPES OF POLITICAL GROUPS. THE FIRST SYMPATHIZES WITH TERRORIST GOALS TO SUCH A DEGREE THAT THERE IS LITTLE CONCERN FOR THE MEANS ADOPTED FOR THEIR IMPLEMENTATION, AND THE SECOND FEARS TERRORISM TO THE EXTENT THAT TOLERANCE OF THEIR DEMANDS, OR CAPITULATION TO THEM, IS JUDGED NECESSARY FOR SURVIVAL. THESE TECHNOLOGICAL, BEHAVIORAL, AND CONTEXTUAL PROBLEMS PRODUCE AN ENVIRONMENT VERY SUSCEPTIBLE TO TERRORIST NUCLEAR THREAT. BASIC TECHNOLOGICAL, POLITICAL, AND SOCIAL CHANGES ARE SUGGESTED FOR HALTING THIS THREAT, INCLUDING USE OF PHYSICAL SAFEGUARDS, REMOTE SURVEILLANCE, AND ARMED GUARDS AT MILITARY AND INDUSTRIAL SITES ON A NATIONWIDE BASIS; LIMITING THE DISSEMINATION OF INFORMATION ON NUCLEAR TECHNOLOGY; AND IMPLEMENTING STEPS TO INHIBIT THE USE OF VIOLENCE BY TERRORISTS, THUS RENDERING TERRORISTS MORE RESPONSIVE TO THREATS OF DETERRENCE AND IMPEDING THE GROWING COOPERATION AMONG TERRORIST GROUPS. REFERENCES ARE PROVIDED. (DAG)