Defensive weaknesses as well as adversarial strengths are examined. Defensive vulnerabilities include weaknesses in the security force, the physical barrier, the sensor/ alarm/closed-circuit television, and the entry control system. Adversarial strengths include speed and force of action, equipment sophistication, and special skills possessed by the adversary. Research consisted of a broad-based literature survey and interviews with nine different types of nonnuclear commercial industries. All the industries had experienced burglary or theft, and five had experienced bombings or bomb threats. Several had experienced robbery, embezzlement/fraud, vandalism/physical assault, demonstrations, or extortion. One had experienced hostage taking/kidnapping. None had experienced arson or sabotage. Little data were available about outside adversaries except that they are likely to have two major skills--knowledge of electronics and knowledge of explosives. They may have a variety of equipment including explosives, thermal lances, core drills, radio scanners, portable transceivers, cryogenics, and computers. Detection and prevention strategies include guard forces, fixed posts, patrols, physical barriers, entry control systems, material handling and inspection, sensors and alarms, lighting, a response force, and employee screening. Various industries also outlined some unique approaches. Tables are provided. Appendixes list the literature survey sources and outline varying levels of security.