Countering Urban Terrorism in Russia and the United States: Proceedings of a Workshop

Potential Consequences	Probability of Occurrence	Technical and Policy Changes	Approaches to Mitigation
Potentially catastrophic-massive loss of life and severe political and economic destruction possible	Moderate over the next five years, with a high potential for surprise	Theft or diversion may not require state assistance and may go undetected if theft occurs in Russia	Improve indications and warnings capabilities
		Stolen or diverted weapons could be converted for terrorist use	Improve security of Russian and Pakistani nuclear weapons at storage sites and borders
		HEU-based weapons smuggled into the United States could be difficult to detect and recover	Accelerate deployment of sensor arrays at critical U.S. entry points and targets
		First responders may be killed or incapacitated by attack	Develop and announce policies to deter use of weapons by terrorist states
			Improve attribution capabilities

A recent book² added radioactive sources to this list and described what the authors called the four faces of nuclear terrorism, as follows:

the theft and detonation of an intact nuclear weapon
the theft or purchase of fissile material leading to the fabrication and detonation of a crude nuclear weapon—an IND
attacks against and sabotage of nuclear facilities, in particular nuclear power plants, causing the release of large amounts of radiation

²	Ferguson, C., W. Potter, A. Sands, L. Spector, and F. Wehling. 2004. The Four Faces of Nuclear Terrorism. Monterey, CA: Center for Nonproliferation Studies, Monterey Institute of International Studies.