Pentagon investigates post-nuclear attack scenarios

The Pentagon has set up a special unit to conduct forensic tests in the event of a nuclear attack on the US, with the aim of identifying attackers for possible retaliation, a Pentagon official said on Thursday.

Major Susan Idziak, a defense department spokeswoman, said the unit was called the domestic nuclear event attribution program. It is made up of nuclear experts equipped with specialist robots for collecting and analyzing fallout at ground zero of any future attack involving a nuclear device or dirty bomb, that disperse radioactive material by using conventional explosives.

The program is principally intended as a contingency in the case of an attack on the US, but the team of experts and specialist robots could also be dispatched abroad in the event of an attack on a US ally.

Whatever target, it would seek to identify isotopes in the fallout in an attempt to establish the particular "signature" of the radioactive material.

The unit's existence was first reported yesterday in the New York Times, which said the program was established by a secret presidential directive, "National Strategy to Combat Weapons of Mass Destruction," signed in September 2002.

Idziak, a spokeswoman for the defense threat reduction agency -- a specialist unit within the Pentagon that oversees the forensic team -- did not provide details of the directive but confirmed the existence and purpose of the program.

The program has dusted off and improved cold war technology for analyzing radioactive fallout. During the cold war, however, the task of identifying an attacker was made easier by the fact that nuclear warheads were mostly mounted on missiles with an identifiable launch point. In the era of the war on terrorism, a nuclear device or dirty bomb is much more likely to be smuggled to its target.