Russia's Threat of Nuclear Weapons in Its War with Ukraine Is at the Heart of the Deterrence Paradox

On Friday 4 March 2022, at the request of President Zelensky, NATO member countries discussed the option of establishing a no-fly zone over Ukrainian territory in response to the total control of skies by enemy aircraft. The option was rejected. The next day, the Russian President reminded countries that such a zone would tempt them to become ipso facto co-belligerents in the conflict. Vladimir Putin did not have to explain himself further to make his point. Almost two weeks after the launch of the war against Ukraine, Russia's coercive use of its nuclear deterrent is being confirmed: literally, the possibility of the use of the country's nuclear forces is deterring Ukraine's friendly states from intervening. The theatres of operation in which the Russian army has a clear conventional superiority are made safe, as is Russian territory.

Accompanying this prevalence of deterrence in the conflict, the nuclear debate, at least in France, has recently been fleshed out with questions about the risk of Russia using low-intensity nuclear weapons first. Experts have been debating for several years the risk of lowering the threshold for the use of nuclear weapons, which could lead to their tactical use in a conflict. The Russian invasion war against Ukraine provides a case in point for live analysis. The question can be formulated as follows: are Russian decision-makers willing to break what is perceived as a major prohibition on the exercise of interstate violence since the end of the Second World War? This issue should not be considered taboo or silly. It is a real question, which cannot be brushed aside. However, the response that can be proposed to it must be cautious.

Theoretically, the question of the use of nuclear weapons arises in two ways: historically, the reasons why nuclear weapons have never been used since August 1945 fall within the scope of a specific field of knowledge: the subject was dealt with a few years ago by Nina Tannenwald around the controversial hypothesis of a nuclear taboo (The nuclear taboo, 2007). This is a fragile thesis because there is no prohibition in the doctrines of the nuclear weapon states, but a series of conditions of use that are envisaged and assumed. It has also been addressed by T.V. Paul from the perspective of tradition (The tradition of non-use of nuclear weapons, 2009): the non-use of nuclear weapons against a non-nuclear weapon state in history would be based on the fear generated by the costs in terms of reputation, which are difficult to calculate and which give rise to a discipline of functional self-dissuasion. Strategically, the question has been running throughout the history of nuclear deterrence since its theorisation at the turn of the 1950s (Bernard Brodie, or Albert Wohlstetter in the United States in the early 1960s, General Lucien Poirier in France in the 1970s, for example).

Bringing this issue to the Ukrainian terrain requires first of all a clear understanding of the Russian nuclear deterrence doctrine and the conditions for Russia's use of nuclear weapons. There is nothing obvious about this on a shared basis, even though everyone may have their own idea or analysis of the subject. Whether it is the concept of "escalation/de-escalation", "escalation control" or "escalation management", the perception of an opening of the conditions for the first use of nuclear weapons has increased since the beginning of the 2010s, even as the arsenal was being expanded with the dual-use capabilities of some versions of new delivery systems (the Russian SS-N-30A, for example, is the nuclear version of the Kalibr missile). This perception is reflected, for example, in the 2018 version of the US Nuclear Posture Review. The success of Russia's dual-use hypervelocity delivery system programmes at the end of the decade reinforced this perception. On the other hand, it can be rightly argued that the threshold for the use of Russian nuclear weapons has probably risen over the past 15 years, with the newfound confidence in the capabilities of pre-strategic conventional systems. It can also be argued that the Russian nuclear doctrine was clarified during the 2010 decade, until the formulation of a specific document in June 2020. Until then, the Russian nuclear posture was covered by the 2010 generic document on the country's military doctrine in general, updated in 2014 in similar terms. In June 2020, Russia made its nuclear doctrine more transparent by specifying the conditions for the use of nuclear weapons, in a document titled On Basic Principles of State Policy of the Russian Federation on Nuclear Deterrence. According to a March 1, 2022 version of its classic paper on Russian nuclear forces, the Congressional Research Service of the United States Congress concludes that the June 2020 Russian paper “does not completely resolve the question of whether Russia would escalate to nuclear use if it were losing a conventional war.” In any case, it must be noted that the subject is objectively equivocal if one crosses rhetorical, doctrinal, capability, and political data. In other words, the nuclear signals that Russia has been sending for several years are part of a deliberate desire to maintain ambiguity on the concepts of the use of force. Practitioners of nuclear issues are well aware that a dose of ambiguity is necessary for the proper exercise of deterrence in peacetime, in particular to avoid threshold effects in the definition of vital interests, for example. But the Russian case illustrates a different kind of ambiguity, one that is designed to foster the instability that, as we can all see today, serves the regime in wartime.

Secondly, asking the question of what the non-use of nuclear weapons is is not at all irrelevant in the case of the war against Ukraine. In fact, the answer to this question is by no means simple or obvious, unlike what is often claimed. As is well known, supporters of nuclear deterrence systematically argue that nuclear weapons are political weapons, not weapons of use, and therefore a stabilising and ultimately a peaceful weapon. Making this argument is not incorrect, but it is incomplete. In reality, for a nuclear weapon to be a weapon of non-use, it must at the same time be a weapon of use, i.e. one whose use is credible in operational terms for the state that uses it as a deterrent, and in perceptive terms for its adversary. The power of the deterrent dialectic lies precisely in this paradox. In France, General Poirier had warned of the risk of weakening the deterrent if all the actors settled into the certainty of its non-use. Repeating over and over that nuclear weapon is only a political weapon produces what the French theorist called "the erosion of the deterrent effect" in a book published in French in 1977: Nuclear Strategies.

Since the beginning of the Russian invasion of Ukraine, it has been clear that nuclear deterrence as used by President Putin's regime is having a real impact on the conduct of the conflict. It is therefore a functional tool. Why is it so? Because no one has complete confidence that Russia will not use nuclear weapons. When it comes to deterrence, a complex and finely tuned discipline, some simple truths are worth remembering.

Written by Benjamin Hautecouverture

Benjamin Hautecouverture is a historian and political scientist, Senior Fellow at the Foundation for Strategic Research (Paris, France). He is Technical Director for Expertise France, Senior Fellow at the Canadian Global Affairs Institute, and one of the founders of the European Union Consortium on Non-Proliferation and Disarmament.