Can Russia defeat America in Europe?

Russia's nuclear strategy towards Europe - how do you organize deterrence against de-escalation with nuclear strikes?

How can the United States and its NATO allies deter Russian nuclear de-escalation attacks? The Russian nuclear strategy calls for the early use of nuclear weapons in the event of a conflict with NATO, with the aim of forcing Western governments to request peace or to risk another potentially catastrophic nuclear escalation. Many Western scientists and analysts have recognized this threat, but so far no clear deterrent strategy has been formulated against it. This article analyzes potential strategies for deterring Russian nuclear “de-escalation strikes” and for thwarting Russian threats of nuclear coercion. He argues that NATO must convince Russia that every nuclear strike will not lead to de-escalation but to further nuclear escalation. In other words, the US must threaten to respond harshly and credibly to Russian nuclear de-escalation strikes, and make it clear to Russia that this could include a limited nuclear retaliation.

How can the United States and its NATO allies deter Russian nuclear de-escalation strikes? Russian nuclear strategy calls for the early use of nuclear weapons in the event of a conflict with NATO with the goal of forcing Western leaders to sue for peace or risk further, potentially catastrophic, nuclear escalation. Many Western scholars and analysts have recognized this threat but, to date, have not yet articulated a clear deterrence strategy for addressing it. This report presents an analysis of possible approaches for deterring Russian nuclear “de-escalation” strikes and for negating Russian nuclear coercion. It argues that NATO must convince Russia that any nuclear strike will not lead to de-escalation, but only to further nuclear escalation. In other words, the United States must threaten that Russian nuclear de-escalation strikes will be met with a tough and credible response, and that the response could include a limited nuclear reprisal.

1 Introduction

The Russian nuclear doctrine for regional wars requires the early use of nuclear weapons in the event of a conflict with an opponent such as NATO. In the context of a regional war scenario for Europe, this could lead to a strategy with which Russia - after a limited and successful conventional war of aggression against neighboring states - wants to force Western governments with the threat of nuclear attacks to seek peace or a further, potentially catastrophic nuclear escalation to risk.[1] This strategy is clearly aimed at confronting NATO with the dilemma of choosing between “suicide and surrender”.[2] The strategy poses problems for NATO, not only in the event of a major war in Europe, but also now. Russia has threatened, and will continue to do, nuclear coercive measures to thwart NATO efforts to counter Russian aggression in its immediate neighborhood, to split the alliance, and to achieve its expansive goals without creating a full-blown conflict.[3] The question is, how is the United States and its NATO allies dealing with this, and how can they prevent Russia from nuclear "de-escalation strikes"?

Many Western scientists and analysts have recognized this danger.[4] Some have begun to propose solutions to this challenge, including options to strengthen US and NATO nuclear capabilities.[5] To date, however, this debate has ignored many important strategic and policy considerations that should be discussed before making recommendations on one's skills. After all, one must first determine one's strategy before one can know what skills are necessary to meet the requirements of the strategy. That's what this post is about.

This paper analyzes possible strategies to prevent Russia from using selective nuclear strikes as an instrument to end a war on Russian terms (nuclear de-escalation strikes) and to negate the Russian threat of nuclear coercive measures. The thesis put forward here is that the Russian strategy is based on the assumption that Russia has an advantage in three relevant areas: Russia's interests in the corresponding regions and countries are more pronounced than those of the core countries of the West, Russia is more resolute than the Western ones States, and Russia has better military capabilities. Therefore, in its response, NATO must try to take these three asymmetries into account. NATO must convince Russia that any use of nuclear weapons will not enable Moscow to achieve its goals, but that Russia will only have to expect prohibitively high costs. In particular, the US and NATO must make it clear that nuclear de-escalation strikes will not lead to de-escalation and will not prevent NATO from pursuing its strategy. They must threaten to respond robustly and credibly to selective Russian nuclear strikes, and possibly also with a limited retaliatory nuclear attack. They must also convince Russia that they have the will and the ability to take this threat seriously. This requires that the US and NATO adapt and improve their declaratory policies, strategic communication, alliance management, war planning and their nuclear capabilities.

To that end, the article analyzes the full spectrum of possible responses to selective Russian nuclear de-escalation strikes, namely surrender, a purely conventional response, a limited nuclear response, and massive nuclear retaliation. This article recommends placing particular emphasis in US and NATO strategy on the threat of limited nuclear retaliation, as such threats may be the only way to provide a sufficiently costly and credible deterrent against the Russian nuclear threat. The recommended strategy is not aimed at copying Russia's strategy and capabilities, but rather, in the words of Sunzu (Sun Tzu), "to thwart the enemy's strategy".[6]

At present, Russian officials seem to believe that limited Russian use of nuclear weapons will induce the Western alliance to give in; the approach recommended in this post aims to prove Moscow wrong. What applies to the US nuclear strategy as a whole also applies here: A potential nuclear retaliation is not threatened because one absolutely wants to wage a nuclear war. On the contrary, nuclear war should be avoided at all costs.

The essay is divided into five parts. First, he analyzes the challenge posed by Russia's nuclear strategy and capabilities. Second, he discusses the weaknesses in the deterrence doctrine of the US and NATO that the Russian strategy is trying to exploit. Third, the paper weighs the possible alternatives for the US and NATO and concludes that the optimal strategy must include the option of a threat of limited nuclear retaliation. Fourth, the paper recommends a targeted approach to address the deficits in deterrence doctrine of the US and NATO, including the associated consequences for NATO strategy, declaratory policy, alliance management, war planning and capabilities. Fifth, it discusses possible arguments against these recommendations.

2 The renewed Russian nuclear threat

In this section we examine the renewed Russian nuclear threat. Since this challenge has already been analyzed in detail elsewhere, we will content ourselves here with a brief summary of Russia's nuclear strategy and capabilities.[7] During the Cold War, the West feared an attack by Russia, including a massive first nuclear strike, aimed at eliminating or weakening the US and NATO's nuclear capabilities. For 25 years after the end of the Cold War, the West did not perceive an acute nuclear threat from Russia, and official documents described this threat as "very low" (remote).[8] Unfortunately, Russian nuclear weapons pose a renewed threat today, but this is different from the one NATO faced during the Cold War. The greatest risk to the use of nuclear weapons today is a limited nuclear escalation in the event of a conventional conflict (selective nuclear strike).

2.1 Nuclear weapons as part of the Russian military strategy

In the event of a major armed conflict with NATO, according to the US government, the Russian strategy provides for the possibility of nuclear de-escalation strikes.[9] For example, Russia could use a nuclear weapon or a small number of nuclear weapons against NATO military targets, such as bases, ground troops, ships or aircraft. It could also attack population centers. Such an attack could be ordered in the late stages of a war to avert imminent defeat. Alternatively, it could also be carried out in the early phase of a conflict in order to prevent the West from relocating troops to conflict areas in Eastern Europe.

This strategy follows the classic logic of limited nuclear war.[10] By using nuclear weapons, Moscow would demonstrate its determination and signal its readiness for a future catastrophic expansion of the nuclear escalation. With only limited use of nuclear weapons, however, the West would still have much to lose. Western Europe and the United States are believed to have remained intact. If Western governments were to continue the war, however, there would be a risk of extensive nuclear exchanges that could threaten Western population centers. Hence, the Russian strategy aims to provide Western governments with an incentive to surrender rather than engage in a potentially uncontrollable nuclear escalation. This strategy is risky and dangerous and could result in nuclear war between Russia and the West. The risk of a nuclear battle between Russia and the United States, while still very low today, is higher than at any time since the most dangerous periods of the Cold War.

Let's imagine the following scenario: Russia is conducting a “hybrid war” -style operation in one of the Baltic states.[11] Unlike the advance of Russian troops into Ukrainian territory in 2014, this would be an attack on a NATO member and the United States would have to respond. Therefore, NATO invokes Article 5 and embarks on a large-scale conventional military campaign to drive Russian forces out of the Baltic States. Faced with the threat of defeat in a war against conventionally superior NATO forces on its borders, Russian President Vladimir Putin decides to use a nuclear weapon against a NATO air base in Poland. Put yourself in the shoes of the US President. How would you react? Would you back down to avert further nuclear attacks, knowing that doing so would mean losing the war and ceding Allied territory to Russia, potentially ending NATO and the credibility of US global assistance commitments? Or would you continue the war or wage your own nuclear retaliation, knowing that it could result in a full nuclear exchange? It is a difficult dilemma indeed, and Russia's strategy is based on the idea that Western governments would prefer subjugation to devastation.

A minority of Western analysts doubt that this “escalate to de-escalate” strategy is really part of Russian nuclear doctrine, but Western decision-makers assume it is.[12] Opposing intentions are always a little uncertain in international politics, and this also applies to possible Russian de-escalation strikes.[13] For realistic threat assessments, one must therefore analyze skills and intentions. As shown in the next section, Russia undoubtedly has the capabilities to implement this strategy. There is also ample evidence of Russia's intentions, including plausible interpretations of official Russian military doctrine; Writings and statements by Russian strategists and generals; explicit nuclear threats from senior Russian officials; Maneuvers that end in simulated nuclear strikes (some of which President Putin himself was directly involved in); Investing in new nuclear weapons (such as nuclear weapons-grade cruise missiles) that appear to be tailor-made for this strategy, and the demonstrative deployment of these capabilities in Kaliningrad, from where selected European objectives can be achieved.[14] In short, there is so much to be said for the fact that the danger is real, that it would be unwise if those responsible in the US and NATO did not take them seriously.

Others claim that the threat of Russian nuclear de-escalation strikes was real, but is now over. According to this argument, Russia relied on nuclear weapons because of its conventional weakness, but now that its conventional modernization is making rapid progress, it relies less on nuclear weapons. In particular, the development of new conventional attack capabilities, such as the calibrate cruise missile, means that Russia can achieve many of the same goals without the cost of nuclear escalation by launching “pre-nuclear” attacks.[15] But Russia is not ready yet. It may intend to use conventional weapons for this purpose in the long term, but at the moment Russia is still heavily reliant on nuclear weapons. Furthermore, the fact that the Russians themselves refer to this type of conventional attack as “pre-nuclear” speaks that it is, or at least could be, a prelude to subsequent nuclear strikes. If the goal of an "escalate to de-escalate" strategy is to "shock" an opponent into giving up, conventional attacks may not be enough and nuclear weapons may be required to achieve the strategic goal.

Still other critics claim that the West misunderstands Russia's nuclear strategy, but in the opposite direction; he overestimated the hurdles for a Russian use of nuclear weapons. Many believe that de-escalating nuclear strikes are a last resort that Moscow would only use in the event of devastating conventional defeat, but these critics ask: Why should Russia wait so long? Rather, Russia is likely to use nuclear weapons at the very beginning of a conflict to prevent NATO from deploying troops to the theater of war and thus prevent a major conventional conflict. If that is the case, and Russia could envisage limited nuclear strikes in a wide range of scenarios, the United States and NATO have even more reasons to develop an effective deterrent against this threat.

2.2 Russian skills

Russia, along with the United States, is a leading nuclear power and it has the military capabilities to implement its nuclear strategy. At the strategic level, Russia maintains a triad of nuclear armed submarines, bombers and ICBMs.[16] Russia is completing a modernization program and has introduced or is about to introduce new systems in all three pillars of its triad. According to the provisions of the New START agreement, Russia will not deploy more than 1,550 strategic nuclear warheads by February 2021.

Perhaps more worrying, however, is Russia's vast arsenal of non-strategic nuclear weapons. This arsenal includes thousands of warheads of varying explosive power (detonation values) on a wide range of carrier platforms. Russia has many warheads with detonation values ​​below one kiloton. Delivery systems include sea-based, ground-based, and air-based cruise missiles, torpedoes, depth charges, air-to-surface missiles, free-fall bombs, and others.[17] Because of this abundance of different detonation values ​​and carrier systems, the tactical nuclear forces of Russia are ideally suited for de-escalating nuclear strikes. Russia is also developing entirely new nuclear systems, such as an underwater nuclear drone, and it is also reportedly modernizing its tactical nuclear forces.[18] For a country going through an economic crisis, these expenditures suggest that nuclear weapons are a priority and occupy an important place in Russian strategy.

3 The deficits in the nuclear strategy of the USA and NATO

The Russian strategy is based on the assumption that Moscow is more willing to take the risks of limited nuclear war in Eastern Europe than Washington and other Western capitals. Classic theories of nuclear escalation, Brinkmanship (Threat to go to extremes) and deterrence claim that a state's willingness to enter into a “contest in risk taking” depends on interests (at stake), determination and ability.[19] President Putin seems to believe that he has an advantage in all of these areas.

3.1 Differences in the weight of interests

President Putin seems to believe that the contentious issues in Eastern Europe are more important to him than to the US, NATO and other Western powers. There is no question that Russia has significant interests at stake. Russia regards much of Eastern Europe as its legitimate sphere of influence. The Baltic States and Ukraine had been part of the Soviet Union and the Russian Empire, and large areas of Eastern Europe had been ruled by Moscow during the Cold War and before. President Putin has declared that the collapse of the Soviet Union was "the greatest geopolitical catastrophe of the 21st century" and that he has set out to restore Russia to its former size.[20] Russia also believes that states on its borders that join security alliances with potentially hostile powers and adopt political and economic models that could undermine the Russian system pose a potentially existential security threat.[21] In addition, many of the countries bordering Russia have Russian-speaking minorities, and Putin has declared that he wants to protect these population groups from alleged discrimination.[22]

From the Russian point of view, the importance of Eastern Europe for the USA is estimated to be much lower. The United States is geographically distant from Eastern Europe and has no strong ethno-linguistic or immigrant group ties with the peoples of Eastern Europe. Before the expansion of NATO, the states of Eastern Europe and the USA never had close political and economic ties. It is easy to see how Putin came to the conclusion that what is happening in Eastern Europe affects him more than the US and that he would therefore be willing to risk more to protect his interests. Indeed, many Western analysts agree with this assessment. Since the 1990s, analysts have been discussing the question of whether NATO's eastward expansion was in the interests of the United States.[23] And in specific foreign policy crises, Western analysts themselves have pointed out that there is allegedly more at stake for Russia in this region. For example, when there was a discussion in Washington following the Russian invasion of 2014 about supplying Ukraine with arms, many experts in Washington claimed that such an approach was unwise, as there was much more at stake for Moscow in the conflict.[24]

3.2 Differences in Determination

The Russian strategy also seems to be based on the assumption that Moscow would be more willing to use nuclear weapons if necessary in the event of war. From a Russian point of view, this assumption is understandable. Since the end of the Cold War, the US has sought to reduce the role of nuclear weapons in its national security strategy.[25] They have also significantly reduced the number of their nuclear weapons. Scientists have described that Western governments are restricted in their freedom of action by a "nuclear taboo" and that the use of nuclear weapons has become "unthinkable" for US decision-makers.[26] These trends may have peaked under President Barack Obama. He declared that he was striving for a world without nuclear weapons and took several concrete steps in that direction.[27] In addition to a strategic preference of avoiding the use of nuclear weapons if possible, the West is confronted with the problem of difficult NATO alliance management and domestic political conflicts in Western Europe. Important decisions have always been made unanimously within NATO, but reaching an agreement among 29 countries is fundamentally difficult. And this is all the more true when it comes to contentious issues relating to nuclear weapons. These difficulties are partly due to internal political factors in the Member States. In some western democracies, nuclear weapons meet with widespread opposition. NATO's decision in the 1980s to deploy Pershing missiles in Europe sparked mass protests in Germany, and some feared at the time that the controversy could break the alliance.[28] At present, the Alliance's traditional leading power, the United States, and vulnerable Eastern European front-line states feel it is necessary to strengthen NATO's deterrent and defense capabilities, while some Western European states are reluctant, largely for domestic reasons. Consequently, the main line of conflict on these issues within NATO is between the United States and Eastern European member states, on the one hand, and some large Western European states, on the other. Indeed, in recent years it has been difficult to reach consensus among NATO members on things as simple as declarations condemning Russian aggression. It is therefore likely that a decision to strengthen nuclear capabilities or to use nuclear weapons would be highly controversial, and action in one direction or another could lead to a rift or even a split in the Alliance. Russia has recognized this dynamic and its strategy aims to capitalize on these rifts.

Russia has no similar inhibitions about the use of nuclear weapons. Because Russia is a highly centralized, authoritarian state, and President Putin could order nuclear strikes without encountering political resistance. In addition, unlike the West, the use of nuclear weapons for Russia is well within the realm of possibility. We now know that Russian war plans during the Cold War called for the immediate and massive use of nuclear weapons, contrary to the theories of gradual escalation that prevailed in the West.[29] And this rather relaxed attitude towards the use of nuclear weapons continues to this day. As mentioned earlier, President Putin and other Russian officials have openly threatened the use of nuclear weapons, major Russian maneuvers routinely ended in simulated Russian nuclear strikes, and President Putin himself has participated in some of these maneuvers.[30] On top of that, Russia's nuclear capabilities are being extolled in the Russian media in a way that would not be possible in the West.[31] Because of these factors, Russian strategists came to the conclusion that if the use of Russian nuclear weapons were limited, the West would simply be paralyzed and unable to react.

3.3 Skills

Russia has an undeniable advantage not only in terms of interests and determination, but also in terms of its capabilities for limited nuclear weapons use. As mentioned above, Moscow has a wide range of nuclear capabilities of different explosive power and delivery mechanisms. In the event of a war with NATO, Russia could use tactical nuclear weapons with significant battlefield effects. For example, it could attack a NATO air force base or a European city with sea, air or ground-based nuclear-armed cruise missiles. Putin could order the use of a nuclear torpedo against NATO ships in the Baltic Sea. Russia could also use nuclear-armed surface-to-air missiles against NATO aircraft. These are just a few of the many other options.

In contrast, NATO has few credible options to respond to such attacks or to wage tactical nuclear war.[32] The only tactical nuclear weapons of NATO are around 200 free-fall bombs, which are stored on bases in several European countries. This is an important capability for many purposes, but in the most likely conflict zones in Eastern Europe, aircraft carrying these unguided bombs are unlikely to be able to penetrate airspaces secured by state-of-the-art Russian air defense systems. Alternatively, the United States and the other NATO nuclear powers, Britain and France, have strategic nuclear weapons, but placing a high-detonation warhead on a strategic delivery system from outside the theater of war risks escalating into a major nuclear exchange, the would put western population centers at high risk of retaliation. The United States could bring nuclear-armed cruise missiles (allegedly containing a low detonation value option) into range with B52 bombers. This option is suitable for a wide range of contingencies, but it also has potential drawbacks in terms of immediate operational readiness, survivability and escalation control in some scenarios.[33] In short, unlike Russia, NATO does not have a flexible arsenal of low detonation weapons that can be deployed in or near the conflict area and that can reliably penetrate Russian air defenses.

4 Weighing possible strategic responses

Deterrence works when you convince an adversary that the costs they would incur if attacked far outweigh the potential benefits the attacker hopes for. In practice, in the nuclear age, deterrence has centered on threats of retaliation. During the Cold War, for example, the United States and NATO developed a number of strategies to prevent Russia from invading Western Europe, under the threat of costly nuclear retaliation. At present, however, NATO does not have a clear strategy for deterring Russian nuclear de-escalation strikes. If Russia carried out such an attack, how would NATO react? In theory, the US and NATO can choose from a wide range of response options. This article does not advocate any prior determination of a specific threatened response to a Russian attack, regardless of the specific circumstances of the individual case. Rather, the author is of the opinion that there should be a general consensus within the alliance on a limited range of options for retaliation which, from Moscow's point of view, are likely to be sufficiently costly and credible to reliably deter Russian aggression.

The specific reaction would of course depend on the particular scenario and would be influenced by a number of factors. An attack with a low-detonation nuclear weapon on a military target would require a different response than a nuclear attack on a European city. The US and NATO would also likely react differently depending on whether they were looking to win or were in a deadlock, and so on. Still, it is possible and useful to consider the general types of response options and their advantages and disadvantages for deterring a limited Russian nuclear attack. Four strategies are currently under discussion: surrender, purely conventional, limited nuclear response, and massive nuclear retaliation.

4.1 Surrender

Some claim that the US and NATO should capitulate in principle in the event of a Russian nuclear strike. In her opinion, it is simply not worth waging a nuclear war over the Baltic states. They claim that Putin would only use nuclear weapons if he really had his back to the wall, and in this situation it would be dangerous to continue a war against him. They acknowledge that there would be a cost to losing a war and not defending a NATO member, but they argue that the cost is less than a massive nuclear battle. They also point out that Article 5 of the NATO Treaty merely obliges the US to assist allies in the event of an attack, but does not provide any details about the specific form in which this assistance must take place. The North Atlantic Treaty contains no clause guaranteeing that NATO will win every war it wages.

There is some logic in this line of reasoning, but the promise to surrender is, to say the least, an ineffective deterrent. Indeed, it is the presumption that the US and NATO would simply back down in such a scenario that reinforced Russia in its recent aggression and nuclear threats. Those who advocate this response would basically allow Russia to do what it wants as long as it is ready to use a nuclear weapon or two. If this is NATO's strategy, why should Moscow stop at the Baltic states?

Moreover, this reaction could well lead to the end of the NATO alliance and undermine the credibility of US global assistance commitments. If NATO did not defend an official ally against an invader, then other states in Europe and around the world would conclude that they can no longer rely on NATO and / or the US for their defense and begin to do things for themselves in a manner that would be detrimental to US security interests. If NATO were found to be ineffective, other larger states in Europe such as Poland or Germany might set up their own nuclear arsenals. One can have an interesting theoretical debate about whether the Eastern enlargement of NATO after the end of the Cold War was in the national interest of the US, but it did happen and it would be irresponsible to expand NATO if it did there was no convincing plan to defend member states. While it is undoubtedly difficult to choose between “suicide or surrender”, an effective deterrent strategy would aim to get the opponent not to attack in the first place, thus averting this difficult decision.[34]

4.2 Conventional response only

Others believe the US and NATO should respond to a limited Russian nuclear attack by conventional means alone. They claim that, taken together, Washington and its allies are superior to Russia in the conventional field and will sooner or later win the war without having to use nuclear weapons. They also rightly point out that the Alliance has a wide range of non-nuclear, strategic weapons at its disposal that could be useful in a larger conflict with Russia, such as cyber, space and missile defense systems and other technologies in development . They also assert that the West has an interest in pursuing its longstanding efforts to reduce the role of nuclear weapons in its security policy. Therefore, the use or threat of use of nuclear weapons would undermine this taboo. After all, they claim that the West is morally superior to Russia and that it would be a mistake to indulge in Russia's level and imitate its nuclear threats and capabilities, or even limited Russian use of nuclear weapons.[35]

This is a consistent position and a purely conventional answer could no doubt remain on the table. But pre-specifying a purely conventional response and ruling out a nuclear response also have significant disadvantages.

First, it is by no means certain that NATO can win a war with conventional forces alone against a Russia that is ready to escalate nuclear. Nuclear weapons are not just symbolic weapons. They can have devastating effects on the battlefield. If Russia uses tactical nuclear weapons against NATO dumping airfields, NATO disembarkation ports, tanks, ships and aircraft, NATO may not be able to mobilize sufficient conventional forces to combat and displace Russian forces. Furthermore, NATO's strategy should not aim to wage a devastating war with Russia, but rather to prevent Russia from doing it, and deterrence means putting yourself in the shoes of the potential aggressor. So the key question is: what will it take to stop Vladimir Putin from attacking a NATO member? The threat of a purely conventional response is unlikely to scare Putin enough to serve as an effective deterrent against a war of aggression.Given the amount of fuss made in Russia's nuclear strategy, one should assume that the political and military leadership of Russia's nuclear threats is appropriate. He would probably not easily challenge a NATO that emphasized the importance of nuclear weapons.

Furthermore, it is in the best sense of US interests if the US is generally expected to respond to a Russian nuclear attack with nuclear weapons instead of avoiding their use as far as possible. If NATO does not exercise nuclear retaliation against a Russian nuclear first strike, what lesson will others learn from it? One lesson could be that the West is morally pure and wants to reduce the role of nuclear weapons in its security policy, but outsiders would also learn other lessons. Vladimir Putin would deduce from this that if he used nuclear weapons he would not have to fear nuclear retaliation, and he might feel encouraged to continue to rely on nuclear weapons in the impending conflict and in his security policy in general. Governments of other countries would conclude from this that in the event of a conflict with the US and its allies they can use nuclear weapons without fear of nuclear retaliation. This would encourage them to focus more - not less - on nuclear weapons in their strategy. Non-nuclear powers would have a stronger incentive to procure nuclear weapons themselves. And the thirty-plus US allies around the world who rely on the US nuclear umbrella for their security may rethink their defense policies. If Washington refuses to use nuclear weapons even in a nuclear attack on an ally, what security does the US nuclear umbrella offer? US allies would have a greater incentive to build their own nuclear arsenals.

This is not to say that a nuclear response has to be the immediate and automatic response to an enemy nuclear attack. The appropriate answer will depend on the circumstances and details of the individual case, all of which cannot be accurately known in advance. But this is also one reason why the US and its allies cannot commit themselves in their strategy to an exclusively conventional reaction to a Russian nuclear strike. There are good reasons why the US and its allies believe a nuclear response is necessary: ​​to deter Russian aggression, to win the war if deterrence fails, and to strengthen deterrence and security on a global scale. In short, NATO needs a credible nuclear option to meet this challenge.

4.3 Massive nuclear retaliation

Others claim that NATO's strategy to deter a Russian nuclear attack should be based on threats of massive nuclear retaliation. In their view, effective deterrence must threaten the things that are most valuable to opponents - and for Putin this is his own life, his position of power and the maintenance of the functioning of the Russian state. The threat of conventional retaliation or even a small number of battlefield nuclear strikes would not be scary enough for Putin. For this reason, NATO's deterrent strategy should focus on massive nuclear retaliation. And in the event that Russia miscalculates and uses nuclear weapons, NATO and the USA would have to be ready to carry out a large-scale strategic nuclear attack against Russia, including against the political leadership in Moscow.

Those who argue in this way are undoubtedly correct in assuming that a massive US and NATO nuclear attack on Moscow and the rest of Russia would come with the prospect of unacceptably high costs. If Putin believed that this was a likely consequence of an attack on a NATO member or the use of nuclear weapons, then he would most likely refrain from it. But is that really likely? Would NATO decision-makers really take this threat seriously? And if not, why should Putin be deterred by this?

Indeed, a massive NATO nuclear response to a limited Russian nuclear strike would not make much strategic sense. Such an attack would put the rest of Europe and the United States at risk of massive nuclear retaliation. The Russian strategy of “escalating to de-escalate” relies on the threat of a limited attack. Even after a Russian nuclear weapon against an air force base in Eastern Europe, for example, Western Europe and the USA would survive it unscathed. However, if NATO were to attack Russia massively with nuclear weapons, Putin could strike back with the intact remnants of his nuclear forces and lay Europe and the United States in ruins; this would cost tens of millions of lives and cause indescribable destruction. Such an approach would not be in the national interest of the USA. If at all possible, the US would prefer to defeat Russia and defend its allies without being the target of a massive nuclear attack.

Hence, Western governments are unlikely to order a massive nuclear attack for strategic reasons, but they would also be cautious for valid legal and moral reasons. It is inconsistent with international humanitarian law and the principles of discrimination (between combatants and civilians) and proportionality to order the killing of millions of Russians in response to a single Russian attack with a tactical nuclear weapon on a military target. Indeed, in this scenario, it is almost impossible to imagine a Western head of state ordering a full nuclear response.

4.4 Limited nuclear retaliation

The final response is limited nuclear war. The US and NATO could respond to Russian limited use of nuclear weapons with their own limited use of nuclear weapons. Scholars have written papers on the logic of limited nuclear war and why it is a rational response for states in a situation of mutually assured destruction.[36] It shows the enemy that one is ready to use nuclear weapons and that the continuation of the aggression carries the risk of an increasingly costly and potentially catastrophic escalation. At the same time, such an approach ensures that the opponent still has a lot to lose. Since most of the enemy’s territory and armed forces have not yet been destroyed, the enemy has an incentive to look for ways out to avert further destruction. In the case of Russia, this strategy would aim to make it clear to Russia that nuclear de-escalation strikes will not de-escalate to Russian conditions and will not deter the US and NATO from pursuing their strategy in the event of a war started by Russia. By making Moscow understand that the use of a nuclear weapon or two is not the way to an easy victory, the Russian strategy is to be thwarted. When Russia uses one or two nuclear weapons, it only achieves that it is attacked with one, two or more nuclear weapons. It would allow NATO to fight fire with fire to fend off Russian aggression. This threat is also credible. It has a clear strategic, legal and moral justification, and it is conceivable that Western governments may order a limited nuclear strike, particularly on military targets or against the political leadership. And unlike a massive nuclear response, it does not expose North America and the rest of Europe to the imminent threat of massive nuclear retaliation. Limited nuclear retaliation does not have to be symmetrical. Washington could vary the number and types of warheads deployed or the targets selected to signal an intended escalation or de-escalation of the conflict. But this category of response differs from the others in that it looks for options in the space between surrender, non-nuclear response, and a massive nuclear attack.

This strategy would not be without risk either. The greatest and most obvious risk of a strategy that relies on the threat of limited nuclear retaliation is that there is no guarantee that the war will remain limited. But at least you have to try, because all other options are riskier. Of course, it is possible that a limited NATO nuclear response could lead to another round of Russian nuclear attacks, which would then trigger a NATO backlash, and so on up to Armageddon. This is a serious risk. In addition, decisions by the leaders would be made in the "fog of war", so that the risk of misjudgments is quite real. But the strategy of limited nuclear war is the only one that has a real chance of deterring further Russian nuclear attacks while preventing a massive nuclear exchange. This strategy is undoubtedly preferable to choosing between immediate suicide or surrender. And, in Putin's view, limited nuclear strikes are most likely a more effective deterrent than threats of a purely conventional response.

Another possible cost of a limited nuclear response is that it would undermine NATO's longstanding efforts to reduce the role of nuclear weapons in its defense strategy. The question of whether nuclear weapons are gaining in importance worldwide provides the decisive information. Since the end of the Cold War, Washington assumed that other countries would follow the example of the United States if these nuclear weapons were given less prominence. However, we have seen that this strategy did not work.[37] As the US and NATO became less reliant on nuclear weapons, other countries, including Russia, moved in the opposite direction. They saw an opportunity to take advantage of the United States' allergy to nuclear forces. Indeed, this strategy has contributed to the current predicament. The US wants to convince both its allies and its opponents that there is no benefit to them if they build nuclear weapons or give nuclear weapons a higher priority in their strategies. The best way to do this is, perhaps paradoxically, for the US to strengthen its nuclear deterrence strategy and doctrine. The threat of a limited nuclear response can serve as an effective deterrent to the threat of Russian nuclear de-escalation strikes and comes at an acceptable cost. This does not, of course, mean that every Russian nuclear attack would, directly or automatically, result in limited nuclear retaliation. As always, the specific response would depend on the circumstances. But there is no reason to assure Putin that he can get away with a de-escalation blow unscathed. To be credible, NATO's nuclear deterrent must at least include the serious option of limited nuclear retaliation.

5 A better NATO deterrent strategy

The US and NATO strategy must make it clear that Russian nuclear de-escalation strikes would lead not to de-escalation but to a decisive response and that this would also include the option of limited nuclear retaliatory strikes. In other words, the US and NATO should seek some kind of nuclear deterrent "during a war" in which they can continue to pursue their war aims of repelling any Russian aggression while deterring a Russian nuclear escalation. In addition, by deterring limited Russian nuclear strikes, the US and NATO can also deter Russia from conventional attack and nuclear threats in general by refuting Moscow's theory of military victories, which is based in part on threats of limited nuclear escalation.[38] To operationalize this approach and give it credibility, NATO must begin to address the three deficiencies in its deterrent strategy that Russia is currently exploiting: weight of interests, determination and capabilities.

5.1 Weight of interests

The US must convince Moscow that its national interests, in the event of a conflict with Russia in Eastern Europe, especially if Russia uses nuclear weapons, will be affected at least as much, if not more, than Russia's interests. Russia's “escalate to de-escalate” strategy is based on the assumption that more is at stake for Moscow in its immediate vicinity than for the US. This conclusion is understandable, but also contestable. For the USA, too, much is at stake in a conflict with Russia in Eastern Europe. For Washington, defending the Baltic states is also about the foundations of the US-shaped international order. If the US fails to defend a NATO member against Russian aggression, it could lead to the end of NATO and the US global military support system. Should Washington fail to repel a Russian attack on Estonia, Latvia or Lithuania, then it is unlikely that Poland would continue to trust the US security guarantee unreservedly. Would Japan continue to bet that the US would protect it against China? South Korea before North Korea? Israel before Iran? If Washington loses Tallinn, it runs the risk of losing Seoul, Tel Aviv and Warsaw too. For Washington, therefore, nothing less is at stake in Estonia than peace and security worldwide and its leadership role in a global, rules-based international order. So it couldn't be at stake anymore. The US must therefore repeatedly convey this message through public and private channels to revisionist regional powers that are challenging US determination to defend regional allies.

Furthermore, the Russian use of nuclear weapons in such a conflict would only affect US interests even more. The US is the guarantor of the global regime of nuclear non-proliferation. They strive to prevent potentially hostile non-nuclear states from building nuclear weapons, to reassure friendly states that they are safe without their own nuclear capabilities, and to deter other nuclear powers from nuclear threats and arms races.

However, if the US backed down after a nuclear de-escalation strike, all of these goals would be jeopardized. Opponents of the US would realize that detonating a nuclear weapon is enough to neutralize the overwhelming conventional military might of the US. The nuclear armed opponents of the USA would increasingly rely on nuclear weapons in their military strategy and would be tempted to threaten early use of nuclear weapons. Non-nuclear states would have even greater incentives to build nuclear weapons, as these could uniquely balance American military power. And US allies would see that a single nuclear strike by an enemy is enough to drill a hole in the US nuclear shield so that they all "get wet". They would have to wonder whether it would really be wise to rely on the US nuclear safety guarantee and they would have to consider alternative safeguards, such as their own nuclear programs.