Your editorial (“Sense and nonsense in the nuclear debate”, 23 July) ends, “Would the world really be a safer place without nuclear weapons? We will probably never know because it will probably never happen.”

This is rather pessimistic, granted the UN General Assembly vote in 1968 strongly supported the Nuclear Non-proliferation Treaty, requiring us to “pursue negotiations in good faith on effective measures relating to the cessation of the nuclear arms race at an early date and to nuclear disarmament ...” This only gets lip service from the current nine nuclear weapon states. How spending £200 billion on building another fleet of nuclear weapon submarines meets that NPT obligation is not explained.

You do not mention the long list of nuclear weapons accidents and human errors that led Robert McNamara, a former US Secretary of Defense, to say that we were saved, over the years, not by our good judgement but by “good luck”. Nor does it explain how one deters those without a territory on which to retaliate or those terrorists who are willing to commit suicide.