Defence CommitteeWritten evidence from Professor Lord Hennessy of Nympsfield, FBA

At the end of the oral evidence session on 24 April 2013, the Chairman, Mr Arbuthnot, asked the witnesses to write to the Committee on the theme of “Nuclear deterrence: does it work anymore?” adding that:

It seems to me that if what you are defending against is a ballistic missile from another state, it is easy to know against whom you are retaliating. If instead what you are defending against is a nuclear bomb, clandestinely put in a container, sailed around the world and ending up in Southampton, which explodes, against whom do you retaliate? And if you do not know against whom you are retaliating, does deterrence as such work anymore?

There is a long historical provenance for part of the Chairman’s question. In deep secrecy in the early 1950s, the possibility of an atomic bomb-in-a-freighter and what we would now call a 9/11 contingency in the air, preoccupied the Chiefs of Staff, their planners and an inner group of ministers.

In September 1950, a group commissioned by the Chiefs of Staff and working under the cover-name of the Imports Research Committee contemplated an atomic bomb in a Russian or Soviet bloc vessel in a British port or “the detonation of an atomic bomb in a ‘suicide’ [civil] aircraft flying low over a key point”. The Committee concluded that: “short of firing at every strange civil aircraft that appears over our shores we know of no way of preventing an aircraft that sets out on such a mission from succeeding”.

Prime Minister Attlee was so briefed as was Mr Churchill, once returned to Downing Street, by the Cabinet Secretary, Sir Norman Brook. Brook explained to Churchill that “I have taken no further initiative to raise the matter since I myself believe that this is a risk against which we cannot at present take, in normal times, any effective precautions”.

It is interesting to note that the first UK nuclear test on 3 October 1952 in the Monte Bello Islands off the North-West coast of Australia was designed in part to examine the impact of an atomic bomb in a freighter alongside in a British port. The device was placed inside a frigate, HMS Plym, to simulate this very contingency.

Should, heaven forbid, such a “suicide” mission have been mounted or an atomic bomb in an eastern bloc freighter destroyed Liverpool or Southampton in a clandestine, pre-emptive strike during a transition from Cold War to World War III, the British government would have known it was Soviet mounted. As the Chairman’s question made plain, no such clarity or certainty would be the case today.

But an examination of the history of the notions of deterrence, the patterns of UK nuclear weapons decision taking fuelled by a trawl through the files at The National Archives suggests that the impulses of various clusters of decision-takers have seen deterrence as a last resort capability in certain highly unlikely contingencies which if they occurred would have devastating consequences for the UK that were “beyond the imagination” until they happened as the immensely secret Strath Report of 1955 put it as part of its investigation of what 10 10-megaton Russian hydrogen bombs would do to our islands.

Clement Attlee’s first paper to his new government’s Cabinet Committee on Atomic Energy, less than a month after the atomic bombs had fallen on Hiroshima and Nagasaki, set a pattern for successive generations of decision takers when he wrote on 28 August 1945 that:

“It must be recognised that the emergence of this weapon has rendered much of our post-war planning out of date … It would appear that the provision of bomb proof basements in factories and offices and the retention of A.R.P. [Air Raid Precautions] and Fire Services is just futile waste”.

Attlee concluded that “The answer to an atomic bomb on London is an atomic bomb on another great city”.

My own view, having surveyed a considerable swathe of the paper trail, of which a collection is reproduced in Peter Hennessy, Cabinets and the Bomb (British Academy/OUP, 2007), is that Sir Michael Quinlan was right to characterize the discussions and decisions overseen by successive Prime Ministers, their nuclear groups and, sometimes, their full Cabinets, to make the UK a nuclear weapons state or to sustain it as a nuclear-tipped nation as “a set of rationales to clothe that gut decision” that this was not the moment to disarm and remove that capacity—that duty to protect against the ultimate, catastrophic contingency, as I would put it—forever. Because once a Prime Minister and his or her Cabinet had so decided, it is almost inconceivable that, given the time, the technology, the money and the skills required, the UK could ever reacquire such a capability. And if I was Prime Minister (a post to which I have never aspired!) I, too, would offer “a set of rationales to clothe” just such “a gut decision” which is why I am a supporter of the like-for-like replacement of the current system and the maintenance of continuous at-sea deterrence.

It is important, as the Chairman’s question implies, to know what, in its various configurations, the UK’s nuclear weapons capability has and has not been designed or provided to do. It is not now and never has been shaped to serve as a deterrent to counter terrorism for example. And, as the Chairman indicates tracing the original provenance of the materials for a primitive nuclear or radiological weapon used against the United Kingdom would not be swift or easy. But because this is so, it is not, in my view a convincing argument to suggest (not that the Chairman did) that the purpose of a UK nuclear weapons capability is pointless because it cannot cover—or deter—all contingencies.

I am struck, too, when eavesdropping retrospectively on the Cabinet Room discussions frozen in the minutes and the memoranda preserved at The National Archives in Kew just how powerfully, when the question of the Bomb has gone on heat, the unknowability of the world in 40 to 50 years time has influenced the premiers and ministers involved.

For example, when Harold Wilson’s tiny Cabinet Committee decided on 11 November 1964, against the impression given in the party’s manifesto for the previous month’s general election, to carry on with the procurement of Polaris, they concluded that “three submarines would represent the minimum force which would be acceptable to us in the event of the dissolution of the NATO Alliance”. (As you know the later decision was for a Polaris squadron of four boats for the purposes of continuous at-sea deterrence).

More recent declassifications have embraced the run-up to the Trident decisions (first C4 then D5 missiles) in the early 1980s. Jim Callaghan’s Nuclear Defence Policy Group (a body created outside the formal Cabinet Committee structure) commissioned options studies for Polaris replacement in the knowledge that the decision would fall to the government in place after the next election (though Callaghan told his colleagues he himself favoured the Trident C4 option).

During a long discussion on 21 December 1978 inside what Callaghan called his “Restricted Group”, there was considerable humility about the predictive powers of those involved when contemplating the constellation of threats the country might face decades ahead. The minutes capture this without attributing views to particular ministers:

The Atlantic Alliance has lasted longer than might have been predicted 30 years ago [ie when NATO was formed in April 1949], but no one could say what would be its future or the future of the United States/Soviet relations in the period to which we had to look forward. Similar uncertainty applied to relations between the two parts of Germany and the Soviet Union and China.

There was a similar flavour to the discussions which took place inside Margaret Thatcher’s Cabinet Committee on Nuclear Defence Policy 1979–82, the most recent declassifications on the paper trail from 1945.

Briefing the full Cabinet on 4 March 1982, when it took the decision to purchase the D5 system from the United States, the Defence Secretary, John Nott, said, in the words of the minute taker:

that the strategic nuclear deterrent was central to the defence of the United Kingdom. No one could foresee what might over the next 30–40 years happen to the North Atlantic Treaty Organisation or to the United States attitude to the defence of Europe. A strategic deterrent under British national control was therefore essential.

There is, I think, a value in eavesdropping on previous rounds of nuclear decision-taking if only to bring a touch of balm to those to whom it falls to wrestle with today’s unknowabilities and intractables (including I would respectfully suggest, the Defence Committee of the House of Commons).

A final offering on that theme. Here is John Nott in a memorandum prepared for Mrs Thatcher’s Cabinet Committee paving the way to the decision to procure what is the current capability of four Vanguard class Royal Navy submarines armed with Trident D5 missiles and UK warheads:

In the midst of a recession with no economic growth, low confidence and an understandable preoccupation with our short term economic difficulties it would be all too easy to wash our hands of this commitment. Our predecessors in both major parties also had economic problems which seemed equally pressing to them but they have kept this country with an independent deterrent ever since the 1950s.

Change the date and that could serve as a National Security Council memorandum today—or a submission to the Defence Committee of the House of Commons.

The need for deterrence against whom and what and when and with what over a 30 to 50 year period is not a thing of confident or even hesitant certainties. That, and for successive Prime Ministers, the possibility that an imperilled country in the future, however remote the contingency, would remember that it was on your watch in No.10 that the ultimate capability for national defence and deterrence was abandoned, combine, in my judgement, to form the arguments that trump when the question arises of the UK remaining nuclear-tipped—the sense of a last resort duty to protect and the gut instinct of which Michael Quinlan spoke.

2 July 2013