First Corbyn was asked by Marr, on the assumption that he might become Prime Minister, what he would say in the so-called Letters of Last Resort, when he would have to "write four letters to the captains of Britain’s nuclear submarines telling them, instructing them what to do if this country’s attacked in a nuclear strike."  After Marr had pressed the point, Corbyn replied that he would give "a strict instruction, follow orders when given."   To which Marr responded:  "So you don’t tell them to fire or not to fire. They don’t know what to do."

   It does not look as if Corbyn had been adequately prepared for this question: the point about the Letters of Last Resort is that they should only be opened if there is no longer anyone left in the government to give "orders". But he went on to say that it would be a disaster for the world if nuclear weapons were ever used, and we can assume that Corbyn as Prime Minister would instruct the sub. commanders not to add more devastation to a nuclear war that had already begun. In the language of nuclear deterrence (and we should not balk at using it) the deterrent would have failed to deter, and therefore there would be no point in using it.

    Alternatively, Corbyn could have said quite reasonably that the contents of the Letters of Last Resort have always been secret and he was not going to break the convention in advance, even if he decided to do so once in office. (Again, it looks as if he had not been properly briefed on this).  At least we might have expected Andrew Marr to ask Theresa May what she had put in those letters, and to press the point as sharply (but of course he didn't when he interviewed her a week later).

    But Corbyn was quite clear on two points in this discussion, first that he advocates a policy of no-first-use of nuclear weapons, and second that Trident will be included in a Strategic Defence Review if Labour forms a government.  It will come as no surprise that his Tory critics while condemning Corbyn failed to address the no-first-use question specifically.  For to denounce no-first-use would require reminding people that it is the official policy of the UK (and its NATO allies) not to rule out using nuclear weapons first, even in the event of a non-nuclear attack against them. The only nuclear countries to declare a policy of no-first-use are China and India, although it is interesting to recall an attempt by Germany in 1998, with some support from Canada, to challenge NATO policy. Not surprisingly, its no-first-use proposal was quickly slapped down by the US, the UK and France.

   On the question of a Strategic Defence Review, Corbyn pointed out that an incoming government often has one. Again, he could have been clearer by acknowledging that current Labour policy supports Trident, but that this will be subject to review. New governments are entitled after all to review the policies they have inherited and there is no reason why the nuclear weapons programme should be exempt -- though it too often has been.

   This is no academic debate. On Good Friday I switched on Radio 4 and heard a cheery voice asking "Are we about to see the start of World War Three"? (it was a trailer for Any Answers).  But this is a debate where we have to work hard, and be well informed, if it is to be raised above the level of ignorance and polemics.

Commentary for Oxford CND Newsletter, May 2017.