Here, from a Federal web site open to the public, is an unclassified summary of what the US Government considers to be the risks from certain natural and manmade threats. Recognize it for what it is: an unclassified summary.
Phi Beta Iota: An interesting effort with potential. It's greatest failure is to avoid any consideration of national riots and armed insurrection in the face of complex inter-acting disasters that turn into catastrophes for lack of intelligence and integrity at all levels of all eight tribes, the government, military, law enforcement, and commerce especially. It's second greatest failure is to ignore the fact that most of our problems are of our own making, and that the single fastest way to secure the USA would be to eradicate corruption and high crimes and misdemeanors now routine at the highest levels of Congress, the Executive, and as with CITIZENS UNITED, the Supreme Court. As marginally clever as this summary is, it is completely lacking in a strategic analytic model, a matrix for identifying and remediating all the preconditions of revolution, and any semblance of a “net assessment” that the Office of Management and Budget (OMB) might use to be effective –but in fairness to OMB, the White House clearly does not want OMB to be effective, just to fake the numbers and keep the theater up until after November 2012.
Charles Perrow, The Next Catastrophe: Reducing Our Vulnerabilities to Natural, Industrial, and Terrorist Disasters (Princeton University Press, 2011)