INCLUSION OF DATA ON THE ASSAULTS ON FOREIGN NUCLEAR FACILITIES, SUCH AS SABOTAGE OF FRENCH REACTORS, YIELDS INSIGHTS INTO THE MODI OPERANDI OF PERPETRATORS OF NUCLEAR TERRORISM AND THEREBY POINTS OUT NEEDED AMERICAN SECURITY REQUIREMENTS. EVENTS USED AS ANALOGS TO NUCLEAR TERRORISM INCLUDE ROBBERIES BY SOPHISTICATED GANGS OF PROTECTED TARGETS, SYMBOLIC BOMBINGS BY POLITICAL GANGS, TERRORIST SEIZURES OF FACILITIES, AND WARTIME INCIDENTS INVOLVING DEDICATED GROUPS ATTACKING DEFENDED AREAS. FOR EACH OF THE INCIDENTS, A PROFILE OF TYPICAL ATTRIBUTES HAS BEEN COMPILED AND A GENERAL PROFILE HAS BEEN DERIVED. THESE PROFILES REVEAL THAT, ALTHOUGH ALMOST ALL OF THE PROFESSIONAL ROBBERIES HAVE BEEN SUCCESSFUL, CAREER CRIMINALS WILL ABANDON A ROBBERY ATTEMPT RATHER THAN RISK ARREST. TERRORIST ASSAULTS USUALLY OCCUR AGAINST UNPROTECTED TARGETS, AND THEIR PERPETRATORS ARE DETERRED BY THE PRESENCE OF ARMED PROTECTION. SIMILARLY, BOMBINGS IN THE UNITED STATES DURING 1965 TO 1976 WERE MAINLY AGAINST TARGETS WHICH LACKED SECURITY SYSTEMS. COMPOSITE ATTRIBUTES FROM ANALOG INCIDENTS INDICATES THE LOW LIKELIHOOD OF A TERRORIST GROUP POSSESSING BOTH HIGH DEDICATION AND HIGH TECHNICAL SKILLS. NEVERTHELESS, SUCH A GROUP COULD EXIST AND COULD BE VERY WELL ARMED. ADEQUATE SECURITY SYSTEMS SHOULD POSE DANGER AND RISK TO ADVERSARIES. TABULAR DATA ARE PROVIDED. (TWK)