Nuclear Wars Cannot Be Won: An Argument for Strategic Deterrence

The increasing polarisation of international politics indicates that the future will be characterised by an intensification of conflicts. And, as the tensions intensify between the world’s two largest nuclear weapons states (NWSs), Russia and the US, and potential nuclear near peer, China, the underpinning principle of the nuclear revolution theory will only grow in salience: nuclear wars cannot be won, and therefore should not be fought. However, the return of great power competition has also galvanised sceptics of the nuclear revolution theory, who reject the logic and tenability of nuclear deterrence and advocate instead for nuclear superiority and a shift toward war-winning nuclear postures. 

In this article, I will argue that an understanding of nuclear deterrence, as engendered by the nuclear revolution theory, is critical in preserving peace and strategic stability. States may choose to pursue superiority, but this article argues that the nuclear revolution theory can more adeptly provide the requisite insights for policymakers and scholars alike to better navigate the challenges inherent in the return of great power competition between China, Russia and the US.

Nuclear deterrence can be defined as the threat of nuclear retaliation against an adversary for an attack on a state’s vital interests, thereby imposing costs that would significantly outweigh any potential gains. The material reality of nuclear weapons, that is their immense destructive potential, informs the principle that nuclear wars cannot be won. Bernard Brodie stated in 1946 that ‘the factor of increase of destructive efficiency is so great that there arises at once the strong presumption that the experience of the past concerning eventual adjustment might just as well be thrown out the window.’

The significance and veracity of mutual assured destruction (MAD) increases when two or more nuclear adversaries possess mutual second-strike capabilities. Additionally, when nuclear adversaries possess larger, qualitatively robust nuclear forces, the reality and risk inherent in MAD intensify. In other words, pre-nuclear-age major power war strategies became obsolete with the advent of nuclear weapons. Whereas once, superiority in the size and breadth of forces had a decisive effect on results of warfighting, in the nuclear age, the size of an NWS’s forces is of less significance. Instead, the efficacy of deterrence rests in the credibility of the threat of retaliation, as opposed to the size and breadth of a deterring actor's forces.

Hence, nuclear superiority is of secondary importance with regards to nuclear deterrence, as even states with small nuclear forces can inspire restraint in larger NWSs. Because all it takes to cause unacceptable levels of damage is for one nuclear weapon to penetrate a state’s defences, the utility of nuclear weapons is limited. As Susan Martin puts it: ‘nuclear warfighting is not a strategy for survival’. This irrefutable reality will remain important in understanding the geopolitical dynamics of the future. Indeed, this outlook is collectively echoed by the five possessor states (P5).

A key concept informing this logic is Robert Jervis’s nuclear danger, which argues that the risk of nuclear war, rather than the nuclear balance of forces, reinforces the value of deterrence: ‘since having more nuclear weapons or more nuclear options than the adversary cannot provide much assistance in terminating war, this posture should not provide a great peacetime advantage’. This dynamic was observable in South Asia, when Pakistani forces crossed the Line of Control into India-controlled parts of contested Kashmir in 1999 (commonly known as the Kargil War). Yet, instead of waging all-out war, India restrained from retaliating with nuclear force despite its advantage over Pakistan. Concomitantly, while Pakistan also possessed the capability to credibly retaliate with nuclear force, the Kargil War eventually de-escalated, and a reversion to crisis stability was achieved.

Because nuclear war would yield no victors, nuclear powers historically loathe to wage direct war against each other. The Cold War provides compelling evidence for this assertion. The Cuban Missile Crisis, arguably the closest the US and USSR came to fighting a nuclear war, eventually ended in compromise between the superpowers. The resulting decision to undertake confidence-building measures, such as establishing a direct hotline between the states’ leaders, is emblematic of the aversion both superpowers had toward risking nuclear war. The rising tensions in East Asia bring the concept of nuclear danger and the irrelevance of nuclear superiority into sharp focus. China’s nuclear capability is roughly 10 times smaller than the US’s, yet the nuclear deterrence relationship between them remains stable.

The Cuban Missile Crisis, the Kargil War, and an understanding of nuclear revolution theorists’ arguments regarding the material reality of nuclear weapons reinforce the idea that superiority is not required for nuclear weapons to have a deterrent effect, and is also not effective at compelling the opponent to yield.

Indeed, superiority is not the decisive factor in crisis de-escalation; rather, it is the possibility of nuclear retaliation even by the weaker opponent that inspires restraint. That over 50 nuclear threats were made in the 20 years following the end of the Cold War, with none of them resulting in all-out war, is testament to the deterrent value of nuclear weapons and to the restraint the nuclear revolution inspires. This pattern suggests that the next 20 years could be no different, if superiority is not pursued. However, if superiority is asymmetrically pursued by an NWS, this would not give them an advantage, instead precipitating an inconclusive arms race, intensifying tensions and plunging the global security landscape into an indefinite state of danger and instability.

Concepts such as the nuclear revolution and nuclear danger will continue to provide a strategic roadmap for policymakers and scholars alike. Nuclear weapons have served most effectively as a deterrent, preventing nuclear powers from engaging one another in direct conflict. ‘Nuclear weapons,’ wrote Kenneth Waltz, ‘dissuade states from going to war’. The historical evidence demonstrates that nuclear deterrence has facilitated peace and stability. As China and Russia strive to challenge the US for global predominance, the underpinning principle of the nuclear revolution theory will become ever more important: nuclear wars cannot be won, and therefore should not be fought.