Big enough to deter

Lord Zuckerman’s recent pronouncements on the nuclear arms race have been favourably received by a large number of people of surprisingly divergent outlooks. His words are piously quoted by spokesmen for CND, and have been endorsed with enthusiasm by Lord Chalfont, the scourge of unilateralists. They have even received the blessing of three of Britain’s former prime ministers. This unlikely amalgam of admirers will not be disappointed by Zuckerman’s new book: it contains something for everyone. But on closer examination, that is what is troubling about it: the universal appeal is maintained, no doubt unwittingly, at the expense of consistency.

The book ranges over a number of important issues. Zuckerman marshals some impressive arguments to show that geographically-limited nuclear war is merely an armchair strategist’s fantasy, and provides a short but persuasive statement of the case against the neutron bomb. He reveals certain economic realities and implications of the arms race and expounds the theory, now associated with his name, that the arms race is in part propelled by the scientists involved in the research and development of new weapons. He exposes the futility of thinking that there can be an effective defence against a determined nuclear attack, and forcefully pleads for a comprehensive ban on nuclear testing.

These are some of the main theses of the book. But its central thesis is that the superpowers must return to a halcyon state of minimal deterrence. The doctrine of minimal deterrence is difficult to define with precision. Zuckerman suggests that a minimal deterrent consists in a nuclear force no larger than that which is required ‘to deter aggression’. How large is that? According to Zuckerman, it is not very large, for in his view Britain’s present independent force ‘is big enough to deter’. Thus ‘the scale of the nuclear forces deployed in Britain and France [should] be taken as a yardstick of what size of nuclear forces are enough to deter in a bilateral [i.e. super-power] context.’ In short, the superpowers could each get by with an arsenal no bigger than Britain’s. This is a striking and attractive view. But it raises questions which Zuckerman fails to address. For example, he refers to an arsenal that is ‘big enough to deter’, but neglects to mention what the arsenal is supposed to deter. This is important, for, while an arsenal like Britain’s might be able to deter, say, an unprovoked nuclear attack on a country’s cities, it would not provide a credible deterrent to such threats as the disruption of shipping or a limited conventional attack. Zuckerman does not seem to recognise that a minimal deterrent can be effective, and remain minimal, only if it aims to deter a quite narrow range of threats of the gravest character.

Second, there is the question whether a minimal deterrent is to be defined in absolute terms or relative to the capabilities of the enemy. In other words, would the size of a minimal deterrent have to vary with the size of the adversary’s arsenal? The answer to this question is extremely important, since it determines whether the US could implement a policy of minimal deterrence unilaterally. Zuckerman never addresses the question directly, but the answer which is implicit in the book is that ‘minimal’ is defined in absolute terms. The UK arsenal is ‘big enough to deter’ the Russians even though their arsenal is vastly superior. Thus the US should be able to reduce its arsenal unilaterally to a size only slightly larger than that of Britain’s – larger since victory over the US would presumably be a more tempting prize than victory over Britain.

Finally, there is the question of whether minimal deterrence could be stable as a long-term policy. There are several reasons for thinking that it could not. The first is that new technological developments could be highly destabilising under minimal deterrence. If, as seems likely, minimal deterrents would be primarily submarine-based, then dramatic advances in anti-submarine warfare could put the major portion of either side’s deterrent at risk. Moreover, effective anti-ballistic missile (ABM) systems might become possible under minimal deterrence. Zuckerman rightly points out that, as things stand, an effective ABM system is a mirage, since ‘it will always be possible to saturate an ABM system with an avalanche of missiles.’ But saturation may not be possible with a minimal deterrent. In other words, the prospects look gloomy, for, as Zuckerman suggests in his analysis of the driving forces behind the arms race, it will be extremely difficult to halt the development of potentially destabilising technologies.

The doctrine of minimal deterrence is also inconsistent with the aim of stopping proliferation, since the reasons for having a deterrent presumably apply to most if not all states. Yet proliferation will ultimately undermine the possibility of minimal deterrence – at least if ‘minimal’ is understood in the absolute sense. Zuckerman obviously conceives of minimal deterrence in a bilateral context. But he would have to concede that the size of one’s deterrent will need to be a function of the number of adversaries one must deter. For each additional adversary, there will be additional cities which must be targeted: therefore one’s arsenal must grow each time a potential adversary acquires nuclear weapons. In a world of proliferating ‘deterrents’, the requirements of deterrence will compel each country to maintain a force far in excess of the minimum envisaged by Zuckerman. In addition to these problems, minimal deterrence would also leave open the possibility of accidental nuclear war, or war through madness or misunderstanding. It is therefore unlikely to be satisfactory as anything more than an interim policy.

As a believer in deterrence, Zuckerman is opposed to the unilateral abandonment of Britain’s deterrent. Other reviewers have thought that his arguments have ‘demolished’ the case for unilateralism, but in fact they leave it wholly intact. He first attacks two claims sometimes made in defence of unilateralism. One is the claim that, if Britain were to renounce its arsenal, this would set an example for other countries. He points out that the US and the USSR would not follow suit, but that does not wholly refute the point. And in any case the point is one which unilateralists would concede cannot stand on its own. Disarmament must be compatible with the security interests of Britain and the West; any influence it might have on other states would be a bonus. The second claim he attacks is the one according to which ‘were we to divest ourselves of nuclear weapons, we would be less likely to be a target in the event of a nuclear war.’ His riposte is that, as a member of Nato, Britain would be attacked whether or not it had nuclear weapons. This response fails to address the unilateralist’s point that, should we be attacked, the attack would probably be less extensive, because there would be fewer targets. It also has the unfortunate implication that it would be better not to belong to Nato, for Zuckerman assumes that, while Nato countries ‘would all be destroyed’, neutral countries would suffer only from fallout and other indirect effects of the war. The only defence he offers for remaining in Nato consists in producing an opaque and irrelevant quotation from Henry Kissinger. It is an annoying feature of the book that Zuckerman often dodges the necessity of providing reasons for his beliefs by simply quoting authorities.

Zuckerman’s only positive argument for retaining the deterrent is that, as an instance of a minimal deterrent, it serves as an example to the super-powers ‘of forces that are adequate to maintain a deterrent threat’. But how realistic is it to suppose that the super-powers will be impressed by Britain’s example? Britain’s example has shone for more than twenty years and they have yet to be impressed. Zuckerman himself, in criticising the similar claim that unilateral disarmament would set an impressive example, asserts that ‘the USA and the USSR ... will clearly decide their policies with respect to levels of disarmament between themselves, and not in response to any gesture that the UK alone might make.’ And, in any case, why would it be necessary to keep the example constantly before their eyes? Political leaders are not wholly incapable of learning from the past.

Not only are his arguments against unilateralism without force, but Zuckerman himself is, without knowing it, a closet unilateralist: for a particular combination of his views adds up to a case in favour of abandoning the deterrent. Zuckerman perceives the value of Britain’s deterrent to lie, not in its independence, but in the contribution it makes to Nato’s total force: ‘the UK’s nuclear effort makes sense only because its nuclear boats and aircraft are assigned to Nato.’ He believes that the British force is ‘big enough to deter’, but that – assuming the Russians have aggressive intentions – it is the Nato force as a whole which in fact holds them at bay: ‘Not for one second do I believe that it is Britain’s nuclear power that deters the USSR from taking action so hostile to the UK’s interests that [Britain] would be driven to independent nuclear action.’ Second, he strongly urges that Nato should build up its conventional defences in Europe: ‘such resources as Nato’s European members can command should be devoted to strengthening [conventional] forces.’ On this point he is undoubtedly right – even if one believes that deterrence in Europe must ultimately depend on the threat to use nuclear weapons. Nuclear weapons are simply not credible as an instrument of first resort in the event of a conventional attack. By relying increasingly on nuclear weapons at the expense of conventional forces, Nato is indeed painting itself into a dangerous corner.

Finally, a factual point which Zuckerman fails to mention is that maintaining an independent deterrent makes it economically and psychologically difficult to maintain adequate conventional forces. Even if Britain does not in the end indulge in the extravagance of Trident D5, the operating and maintenance costs for Polaris over the next ten years will not be trivial. Earlier this year the MoD ordered about a hundred new Polaris rocket motors at a cost of several hundred million pounds. Furthermore, because people entertain certain illusions about the importance of nuclear weapons, nuclear weapons tend to divert public attention away from conventional defences. They also reduce people’s willingness to engage in national defence by making conventional service seem futile.

If we put these various points together with the fact that, as a believer in minimal deterrence, Zuckerman holds that the Nato nuclear arsenal is ‘miles in excess’ of what Nato rationally requires, then it is easy to see that he has produced an argument for unilaterally abandoning the deterrent. If the deterrent makes sense only in its role as an integral part of the Nato force, and if the Nato force is overgrown, so that much of it is superfluous, then one way of making the force more ‘minimal’ would be to eliminate the British contribution. And if it can be eliminated it ought to be, for otherwise it will absorb resources which could instead be devoted to the vital task of strengthening Nato’s conventional defences. This argument for giving up the deterrent is certainly more plausible than Zuckerman’s arguments for retaining it. I began by noting that Zuckerman has spread his banner so wide that there is room for virtually everyone underneath. But the critical reader will not find it comfortable to remain there for long. He may be grateful to Zuckerman for dislodging him from one of the many positions Zuckerman has exploded, but he will feel the need to move beyond the doctrine of minimal deterrence to a more coherent and defensible solution to the problem which nuclear weapons pose.