resulting from human error and infrastructure that fails to be sufficiently robust. Russia³ and Japan⁴ have taken the view that the newest and most threatening form of disaster—terrorism—should be considered as an extension of the threats for which cities are historically organized. This is the right way to analyze the problem, that is, looking more broadly at safety and security, including terrorism, for two reasons: (1) The agencies and officials who are responsible for dealing with earthquakes, fires, power blackouts, and riots must, in most cases, use the same facilities and capabilities for coping with terrorism, and (2) only this approach allows an affordable and sustainable effort.

Megacities⁵ differ from smaller cities not only in their enormous size and high growth rates but also in both the depth and the range of their resources and the complexity of assuring the reliable functioning of all the services on which the city’s life depends. Megacities do enjoy concentrations of valuable human and physical resources, but while natural disaster response capability is extensive in many megacities, it is often not sufficient to prevent wide-scale destruction and loss of life. In some megacities neither resources nor political will are sufficient to make megacities significantly less vulnerable. Transportation facilities, for example, may not be adequate to provide for emergency evacuation when necessary. As cities have grown faster than municipal governments can build and adapt their infrastructure to cope with disasters, capabilities such as public transportation have failed to keep up with emergency requirements.

Now one must add to natural and technogenic disasters the threat of social violence, of which the most extreme form is catastrophic terrorism. Social unrest, and its extreme form, terrorism, are very old threats to established societies. In the wake of the end of the cold war, new forms of conflict have proliferated, stimulated by ethnic rivalries, political insurgencies, and religious bigotry, often with deep historic roots. From 1989 to 1999 major incidents of social violence took place in 34 major cities around the world, including some 15 in the Middle East and Asia. The character of the resulting conflicts has changed, however, with civilians as both the targets and the instruments of terrorism, and with new technologies (including the so-called weapons of mass destruction) dramatically expanding the potential for death and destruction.