From the thesis introduction: "The initial focus of this paper was to identify the five (5) most critical areas with respect to the integrity and security of the Nation's borders. However, as the research progressed it became clear that it is not the threats themselves -- namely terrorism, narcotics trafficking, and proliferation of CBRN [chemical, biological, radiological, and nuclear] weapons -- that pose the most critical threat to the United States, its interests and citizens. The real threat lies in the potential for a failure to unite the efforts of the entities charged with addressing perceived or identified threats. Intelligence shows that these threats are persistent and can materialize and adversely impact us at any time, anywhere, to threaten our most cherished right - freedom."
Defense Technical Information Center (DTIC): http://www.dtic.mil/dtic/