Many refer to the current proliferation of terror as the age of “think the unthinkable”(Bracken, 2001, 173). The latter term is not novel to society (e.g., used decades ago to describe nuclear war). Nor are we ignorant to consequences of diverse forms of warfare (of which terror is a variant). Yet, we are aware of the growing global public concern about terrorism which accentuates the need to address this exceptional threat within our communities. Discussions about how to respond to the events of September 11, 2001 and to the global propagation of terrorism have stimulated a controversy regarding the handling of such threat. Some argue that terrorism is indeed a new hazard about which the modern world, and specifically the US government, knows very little. Others believe that a history of dealing with man-initiated threats, such as warfare and crime, as well as fifty years of research on natural hazards and disasters, provide a solid base of relevant knowledge. These views are exemplified: (a) in the frequent political labeling of this threat as the new war of our era (Pillar, 2001; US Department of State, 2003) as it offers the dangers of battle (US department of Justice, 1999); (b) in legislations -- regarding it as an unlawful criminal activity (Pillar, 2001; Combs, 2003); and (c) in developing an all-hazard approach (for terrorism, natural and technological hazards) under one umbrella of homeland security (Office of Homeland Security, 2002). The paper deals with this controversy and analyzes the question of whether terrorism should be addressed by planners and architects as a new form of threat, or whether it can be dealt by utilizing existing knowledge from other domains. Specifically, this paper focuses on the utility of the research and accumulated experiences on natural and technological hazards as a potential source of relevant information to counter terrorism. It should be noted that the analysis of lessons to be learned from the studies of crime within the built environment of communities (Healy, 1983; Saarinen, 1976; Jacobs, 1961; Newman, 1972; Tijerino, 1998). The objective of this paper, therefore, is to evaluate the potential of knowledge transfer from established domain of hazard and disaster mitigation to the realm of terrorism in the built environment. To accomplish that, the paper offers a discussion of the similarities and the differences between terrorism and natural/ technological disasters. In addition, a review of existing areas of study of hazard and disaster mitigation, including specific technologies and developed policies, is presented. The reviewed material is evaluated by its relevance to the built environment and applicability to terrorism threat. The paper indicates new areas of research that need to be addressed to successfully prepare for and respond to terrorism