Beyond Deterrence

And its limits in the Russo-Ukrainian War

A Yars nuclear missile complex driving through Moscow during reheasals for this year’s “Victory Day” parade.

The concept of ‘deterrence’ has dominated strategic discourse in the West for some 75 years. It describes the supreme quality that western governments expect from their military establishments, and in particular from their continuing investments in nuclear capabilities. The fixation with deterrence began during the Cold War when it was hard to think of any other role for nuclear weapons. It now continues because it was judged to be successful then, only with the expectation that somehow it can be made to work on a wide range of contemporary security threats that may be quite unrelated.

It is also discussed as an effect that can largely be achieved simply by being strong enough. The result is that when things happen that we don’t like this is described as a failure of deterrence even if nobody had previously suggested that there was anything that needed deterring. This encourages a relatively passive approach as if sufficient strength and a demonstrated readiness to use it will mean that deterrence occurs naturally.

Why do we like Deterrence?

Deterrence is a ‘goldilocks’ concept, not too hot and not too cold. It implies a defensive intent without weakness, a determination to prevent aggression without being reckless. To adopt a deterrence strategy is to signal that there is no urge to fight but that there are interests sufficiently vital that they would be fought for. It sustains rather than disrupts the status quo. This is what it did during the Cold War. It thus has positive associations that other potential strategies lack. Appeasement as a deliberate strategy has been discredited since the 1930s; conquering other states is now seen to be as demanding as it is illegal. Deterrence therefore has an inherent normative appeal. There is no dishonour in deterrence.

The etymology starts with the Latin deterre - ‘to frighten from or away’. The salutary effect of the threat of punishment has been the key feature. When nuclear weapons came along the only positive benefit was seen to be that the threat of being struck by such weapons would persuade potential aggressors to hold back. Deterrence was about a state deliberately threatening great hurt on another unless there was compliance with its wishes.

A nuclear monopoly might tempt a state to try to coerce anybody about anything. But the US monopoly only lasted while the weapons were scarce. In 1949 the Soviet Union tested an atomic device and in then both superpowers moved to ‘city-busting’ thermonuclear weapons. After this point, even when military planners and civilian think-tankers tried to think of clever ways to employ nuclear weapons to win wars, prudence kept on pulling them back to deterrence.

Possessing a nuclear arsenal could be presented as morally shameful but it became just about acceptable when its role was to deter others from using their nuclear arsenals, and when there was good reason to assume that deterrence would work. Fortunately nuclear deterrence did seem to work, better in practice than in theory: there have been many terrible wars and great violence, and they still occur far too often, but as yet nuclear powers have not gone directly to war against each other.

Yet the association with nuclear weapons still made deterrence controversial. Those arguing for complete disarmament claimed that the deterrence effect was a chimera, used to rationalise holding on to weapons that were kept for other reasons, either to satisfy the military-industrial complex or some deep psychological fantasies about ultimate power. Abolitionists wanted to show that there was no risk in disarmament and so the weapons had no strategic value. What were thought to be deterrent successes, they argued, had other causes or could have been achieved by other means. Every example of a non-nuclear power taking on a nuclear power was cited to show the limits of nuclear deterrence even though these were usually limited contingencies (for example Argentina’s seizure of the sovereign British territory of the Falkland Islands).

All this often led to playing games with history to make a point. It was of course entirely possible that there would have been no Third World War even if nuclear weapons had never been invented, but in the post-1945 world at crucial points nuclear weapons acted as a vital source of restraint. Over time the idea that it would be madness to even think about embarking on a war that could end with a civilisational catastrophe was sufficiently internalised that mutual deterrence worked with little effort.

The Concept

The Cold War nonetheless flattered deterrence. It was credited with the West’s success in containing the Soviet threat. The policy stress on deterrence led to the concept being thoroughly explored to better understand how it worked and might be reinforced at times of crisis. An elaborate conceptual framework took shape, which facilitated strategic analysis and academic study but also left deterrence harder to pin down.

The core problem was explaining how deterrence could work when the adversary could counter a nuclear threat with a counter-threat of its own. What had appeared straightforward during the brief period that the US enjoyed a nuclear monopoly became complicated once the Soviet Union acquired its own arsenal.

The initial response was to assume that this simply meant that the nuclear arsenals would now neutralise each other and so wars would then be conducted along the lines of those of the past as if these weapons did not exist. But that seemed to presume a lot of restraint and, anyway, while the US enjoyed nuclear superiority if not a monopoly it did not back away from deterrence but instead made it even more important. An adversary must know that if it attempted aggression it risked a massive nuclear response. This became obviously problematic as the Soviet Union began to catch up.

The likelihood of retaliation undermined the credibility of the threat, even though the Soviets could never quite rule out an American strike even if this came less out of a cold calculation and more an emotional impulse in the chaos of war. Given the high stakes, a non-negligible risk that nuclear war could happen might be all that deterrence needed. The slightest possibility was a strong argument for caution and restraint.

If this still seemed too risky there was an alternative, and somewhat more rational, approach. Instead of relying on Soviet calculations being influenced by the slight possibility that nuclear weapons would be used in retaliation, might it not make more sense to make it harder for the Soviets to aggress in the first place by building up NATO’s defences? Deterrence did not have to be about punishment.

This led to a definition of deterrence as occurring when a target is persuaded that the prospective costs of any aggression will exceed the prospective gains. It was then possible to consider manipulating the expectation of gains as well as those of costs. Imposing costs, which is what it was originally all about, just became one type of deterrence - ‘deterrence by punishment.’

Preventing gain by demonstrating an ability to stop aggression in its tracks became known as ‘deterrence by denial’. This could be achieved with strong conventional forces and so did not carry the risks of nuclear punishment. This opened up different ways of deterring, away from the extreme scenarios involving nuclear weapons. All sorts of objectionable activities might be deterrable if only likely perpetrators could be shown that they would probably be thwarted. And once one was talking about lesser contingencies then there might be alterative forms of punishment that could be employed that did not involve mass destruction.

Debates about how to cope with the extreme contingencies continued for the duration of the Cold War. But over time, and despite some rocky moments in the late 1970s and early 1980s, East-West relations stabilised. With no crisis forcing matters to a head, but just occasional flurries of anxiety, deterrence began to be taken for granted. The essential calculations became embedded in the thinking of all key actors and lost all sense of urgency. They became internalised. The preparations for war continued as part of the routines of alliance and defence planning but political leaders saw no need to put their countries on a war footing.

Out of this emerged a distinction between general and immediate deterrence. With general deterrence relations between states have been antagonistic for some time yet the antagonism has long lost its edge. With immediate deterrence the antagonism is sharp, dangerous and urgent. Deterrence has not been internalised but is barely working at all. That is why there is a sense of urgency and crisis. Most deterrence relationships start with an immediate crisis. If managed successfully the threats and forces may still stay in place until eventually a point is reached when a resumption of crisis conditions appears unlikely. The would-be aggressor not only holds back for the moment but stops thinking of aggression as a serious option. The deterrent effect becomes institutionalised.

The equilibrium in East-West relations was lost in 1990-91 as the Soviet Union and then its communist alliance collapsing (with most of its members then joining NATO) leaving Russia insecure. Political relations generally became more complex and fluid, so it was less clear where deterrence was needed and how it might be achieved, especially as non-state actors, including vicious terrorist groups grew in importance. Techniques such as cyber-attacks and information operations were found in a ‘grey area’ of offensive capabilities that fell short of full-scale war.

Deterrence was no longer required just to solve one big problem. Instead it was called in aid to solve many small ones. It might have moved from being the dominant strategy to one of the many instruments available for addressing a variety of contingencies, some quite unique. Instead policy-makers stuck with the idea that we could find ways of deterring all aggressive and obnoxious acts through a demonstrated ability to respond when required.

Deterrence as an All-Purpose Strategy

The purpose of a deterrent strategy is to stabilise situations. The more stable they become the more successful the strategy and the easier it is to sustain. As a situation becomes unstable and dangerous, deterrence strategies become more important but also more difficult. Indeed it is arguable that when deterrence is at its most immediate and urgent it is most likely to fail. It is also easier to concentrate on a particular and important strategic relationship, as was done during the Cold War, than cope with many different types, varying in character and severity, as is required now. What might work in one case might not work in the other. In some cases a vague threat of punishment might suffice: in others more denial is required, which means building up defences and increasing resilience.

And then we face a basic problem when it comes to assessing what makes deterrence work. This is because successful deterrence means that nothing happens. It is about persuading an adversary not to act. But there are many possible reasons why nothing happens: the adversary may have held back because of an explicit threat; they may have already assessed the risks for themselves and decided not to act; some other factor made them change their plans independently of any threats; they had planned to act but then couldn’t be bothered because it would be too much effort: or they had never intended to act in the first place.

We do know from cases where deterrence has patently failed that this often was the result of problems of misperception and misapprehension. The would-be deterrer missed the signs that an adversary was up to no good or delivered the deterrent threats too late or in a muted or confusing fashion. Or the target misinterpreted the threat or did not take it seriously enough.

This produces a paradox. Deterrence may be working very well without us being aware of it for much of the time. So we can issue deterrent threats as part of a deliberate strategy and have no effect, yet benefit from formidable deterrent effects without issuing any threats because an actor recognises all the reasons why an aggressive move might fail or cause unwanted trouble and so does nothing. Deterrence thus happens all the time without much prompting, but when there is a prompt it may nonetheless fail.

Deterrence and Foreign Policy

Deterrence was developed as a strategy to cover the most dangerous contingencies. During the Cold War national survival and the integrity of alliances were at stake. It was reasonable to assume that direct challenges to these most vital interests would be taken seriously even if the response was fraught with danger. That should remain the case. But the approach becomes problematic when the challenge is to lesser interests, especially if there is any equivocation about how much they really matter.

Adopting deterrence as an overall strategy to cover all eventualities is not going to work. Because the circumstances in which deterrence might work are so various there can be no standard formula suitable for application in all circumstances. What might succeed when the most vital interests are engaged will be less effective when the stakes are lower. Even an approach that worked once might not work again in apparently similar circumstances, because the target now knows what to expect and can prepare accordingly.

It is notable that Israel, a country that is both regularly at war yet makes deterrence a feature of its security policy, seems to accept that deterrent effects fade over time. Hence whenever it is fighting its neighbours it talks of ‘restoring deterrence’ as if there is a natural equilibrium to be found if only it can remind its adversaries about how unwise it can be to pick a fight with Israel.

When adversaries are assumed to be unremittingly hostile then there is no way out of bouts of deterrence interspersed with war, unless one of the wars turns out to be truly decisive. If the aim is to use the breathing space allowed by successful deterrence, then threats can be combined with inducements, adding carrots to the sticks.

This is why care is needed when tempted to attach deterrence to every foreign policy concern. Not all issues can be given the same priority. Deterrence works best when the threats of punishment or the preparations for denial are linked with vital interests for that makes it more likely that the threats will be acted upon and the defences will be resolute. It does not work to adopt a ‘punishment fits the crime’ approach, as if deterrence can be tailored to the interests at stake, so that a relatively minor concern requires only a limited effort. Military preparations must always be sized according to the enemy capabilities and intentions.

Deterrence and the Russo-Ukraine War

The last few years have seen deterrence mentioned often. Russia has regularly directed threats to both Ukraine and its Western supporters. The experience to date provides some clues about how deterrence can work in practice and the pitfalls of over-reliance on threats. A number of points emerge, which are consistent with the experiences of other conflicts.

The starting point is that deterrence and nuclear weapons are still closely linked in the perceptions of both policy-makers and the wider public. Nuclear exchanges are still what comes to mind when there is talk of deterrence and also escalation, another Cold War concept geared to managing the risks of major war. This terrifying prospect, with all the chaos, death and destruction it would entail, is a deterrent in itself. It continues to influence behaviour. It explains why NATO is not fighting side by side with Ukraine and why Russia has not mounted attacks against NATO states. There is a natural concern in the unstable situation we currently face about whether deterrence in this form will hold, but so far it has done so.

Other threats of punishment have had less obvious effects, even when they have been implemented. The most obvious example is economic sanctions which the West threatened prior to the full-scale invasion and subsequently implemented. It is easy to understand why Putin did not take this threat seriously. He hoped the war would be over before the US, UK, and EU got their act together. Past experience suggested that enforcement would be patchy and that circumvention would be possible. Now sanctions are partially justified as punishment but more so as a means of weakening Russia’s capacity to continue with the war.

For its part Russia created an energy crisis to accompany its full-scale invasion in the hope of persuading European countries to back off helping Ukraine. This was a concern of European policy-makers before the invasion but in the end it did not stop them providing assistance to Ukraine.

Vladimir Putin has resorted to ominous threats of varying levels of specificity to deter moves from NATO countries designed to shore up Ukraine. He has not been short of terrible things to do to Ukraine, but having set one red line after another, he has floundered when they have been passed with his warnings ignored. His threats have declined in credibility because of their regular and largely ineffectual use.

There have been examples of concerns in the US about what Russia might do, especially with nuclear weapons, that has led to forms of support being ruled out because they might be unduly provocative. The most notorious example of this was refusing to allow Ukraine to use Western systems against targets in Russia even though there was no obvious reason why this would be an unbearable development for Russia, when targets well inside Russia were already being attacked by Ukraine with its own systems.

While the Russians were regularly setting red lines, the West did not do so. The only explicit red line that was warned could lead to a significant Western response was the use of nuclear weapons against Ukraine. But other developments that might have been anticipated – from attacks on residential areas and critical infrastructure, interference with sea traffic through the Black Sea, and introduction of foreign troops, were not subject to any warnings in advance. Levels and types of Western support for Ukraine has not been made conditional on Russian behaviour so much as what the donating countries can find and afford and Ukraine’s military plans.

In dealing with many of the most egregious Russian actions denial has been more important than punishment. Much of the Ukrainian effort has been about stopping Russian offensives succeeding, including cyberattacks and efforts to take out electricity supplies. It might be hoped that demonstrating that certain acts are futile would lead Russia to stop trying, but in practice most of Ukraine’s defensive effort have been to limit harm rather than to establish ‘deterrence by denial’. Other than nuclear use the main boundary waiting to be crossed may be strikes on decision-making centres and political leaders (which has been threatened by Putin and to a degree was attempted in the first days of the invasion).

Lastly there is now a wider Russia-NATO confrontation underway that thus far has not turned into a shooting war but involves all other forms of power – including finance, trade, and energy, as well as terrorism/sabotage, attacks on underwater cables, cyberattacks and information campaigns. These activities are not about deterrence but attempts to bring the war to a conclusion. It may be possible to frustrate some of these activities, and that may have some later deterrent value if they can be shown to be futile and counter-productive. They are currently being countered to prevent disruption rather than to make a deterrent point.

During the Cold War deterrence helped to stabilise further a system already tending to stability. When a confrontation has moved to an active phase it is less useful and that is where we are now, with security forces on the alert for malign behaviour and new means being developed to limit any effects. It may be that Western agencies are looking for ways to make Russia pay more for its hostile stance, although if this is being done it is not being publicised. There is no reason why Russia should be immune from the sort of techniques it is applying against the West. NATO countries are finding that they need to move away from the passivity implied by a deterrence posture to the constant activity demanded by a developing security crisis with the Russian Federation.