Dust defense

Dust defense, sometimes called environmental defense, was a proposed defensive measure that would destroy enemy ICBM warheads attempting to attack the US Air Force's Minuteman missile fleet. It consisted of a large number of nuclear warheads buried between US missile silos, which would be triggered as the enemy warheads began to approach the bases. This would throw huge quantities of dust high into the air, which would abrade the incoming reentry vehicles, destroying them. It would also create enormous amounts of fallout which would kill tens of millions of US civilians, and the concept was never seriously considered for this reason.

A variation of the dust defense was the basis for the Dense Pack deployment option for the MX missile. In this case the individual silos were built to survive any near miss, so the enemy warheads would have to impact the ground very close to the silo to destroy the missile within. This explosion would throw up dust, thereby creating a dust defense. Although this also caused a similar amount of fallout, in this case it was the enemy doing it, and they would do so anyway in any attack on the US silos.