asked the Minister of Defence if he will state the criteria on which he assesses the nuclear damage a potential aggressor would accept.

No potential aggressor would be likely to regard any major nuclear exchange as acceptable.

Does it occur to the right hon. Gentleman that the potential aggressor is also thinking in the same terms as he is and making the same sort of assessment? If it is true, as the Prime Minister assures us every day, that Russia is the potential aggressor, is the Minister of Defence saying that we could accept the same amount of nuclear punishment which Russia can accept, particularly in view of the fact that Russia controls her nuclear weapons and we would use them only by permission of America?

I think that the hon. Gentleman has stumbled upon part of the truth in saying that it is this mutual and provident fear which is the essence of a deterrent.

Is my right hon. Friend aware that, to match his replies, brevity in supplementary questions from some parts of the House would be greatly welcomed?

Is the right hon. Gentleman telling us that at any period in history man has ever feared the weapons which he used?

I should have thought that all mankind today feared a nuclear explosion.