The right hon. Gentleman's premises are interesting, but they are not quite up to date. The spectrum of deterrence will not be dramatically altered by the zero option if we take into account that submarine-launched ballistic missiles and air-launched missile systems will remain. The right hon. Gentleman says that if intermediate range ballistic missiles go we shall not be able to inflict massive destruction on centres of population in the Soviet Union. That is not so, since strategic deterrents will remain and many medium-range systems of other types will remain.