Following the events of September 11, 2001, many countries began new efforts targeted at improving the security of their nation. These have included additional security at border entry points, new procedures for screening materials entering the country, an increased focus on intelligence information gathered at home and abroad, and the preparation of emergency response personnel who must deal with terrorist incidents.

Each of these activities presents new problems, new tactics, and new ways of looking at familiar situations. Becoming proficient at any of these will require new forms of training that focus on issues unique to Homeland Security (HLS). Within the US Departments of Defense, Justice, and Health there are numerous efforts examining the best ways to create training scenarios, facilities, course materials, and simulations. Our team has identified a number of existing simulations that have the potential to address HLS issues. We have also defined some high-level requirements for new simulations in this domain.

The study of existing simulation categorized those systems as: leadership training, immersive systems, desktop trainers, analytic simulations, and simulation support tools. In this paper, we will introduce many of these systems and identify those that we believe are the most immediately applicable to different forms of HLS training. The large number of potentially applicable simulations indicates that HLS organizations should not engage in the development of a new simulation system before they have studied, experimented with, and applied several of the systems identified in these studies. Organizations can make more efficient use of their financial resources by applying them to the gaps that exist between available simulations, rather than paying to reinvent those capabilities. The study also indicates that existing simulation systems, usually from military or medical organizations, are targeted at the actions that should be taken in response to an emergency event. But, we were able to find very few simulations that focused on planning for an emergency, identifying threatening situations, or preventing an event from occurring. In these areas, it appears that new simulation systems will have to be constructed.