Nuclear Decapitation is a
nuclear war scenario in which the
command structure of a nuclear power (in the U.S., known as the
NCA) is attacked via surprise
nuclear strikes. The goal is to
disrupt enough levels of the command structure quickly enough that the nation
under attack cannot
marshal its own
nuclear forces to retaliate. This is, naturally, an extremely risky business; one assumes that the forces of the nation under attack have no
standing orders to retaliate in case of loss of communications with the
head office. It is made only slightly
more feasible by the existence of
PALs whose codes must be
disseminated by a national command structure in order to use nuclear weapons, given that PALs can be reprogrammed or their codes pre-distributed.
The SSBN is probably the strongest deterrent against such a strike. Ballistic missile submarines at sea are (at present) nearly impossible to locate and target reliably. In the case of the U.K. government, at least, we know now that one of the first duties of an incoming Prime Minister is to hand-write a set of orders for the commanders of such submarines, to be opened in the case of a successful nuclear attack on the United Kingdom. The content of those orders is kept tightly secret while they might be used (i.e. until they are superseded by a new Prime Minister's policy). Generally, past Prime Ministers have revealed their orders to be one of several options: retaliate against a known enemy, surrender their submarines without firing, or turn their submarines over to the command of either another Commonwealth nation such as Australia or to the United States.