Nuclear weapons are becoming smaller, deadlier and more precise. Information on their fabrication and use is more readily available. Many weapons can be relatively easily constructed by hobbyists or those with access to the appropriate equipment or materials. The essential components of a neutron bomb can be carried in a back pack, and the rest are obtainable from local electronics and hardware stores

In 1970 the city of Orlando, Florida, made ready to pay a $11 million ransom to a terrorist who claimed to have stolen fissionable material from the Atomic Energy Commission and made a hydrogen bomb. The culprit turned out to be a 14 year-old boy. With his ransom note he sent a workable diagram for a hydrogen bomb, though this does not mean he had the capability to build one. There were 43 less credible threats in the USA between 1970 and 1979

The dismantling of warheads during the 1990s will lead to an estimated surplus of 50 tonnes of virtually pure weapons-grade plutonium some of which security officials fear will fall into the hands of rogue governments or terrorist groups