1. Introduction
The 2018 US Nuclear Posture Review (NPR), with its interpretation of Russian doctrine, and the slow demise of the Intermediate-Range Nuclear Forces (INF) Treaty have heightened concerns about transatlantic security. Similarly, the possibility that nuclear weapons systems can be subject to interference during peacetime, without the knowledge of the possessor state, raises questions on the reliability and integrity of these systems, with implications for decision-making, particularly with regard to deterrence policy.
Even – perhaps especially – where their own views of deterrence diverge, experts and decision-makers should collectively discuss points of divergence and identify common ground on which to build a secure and peaceful world order.
Researchers at Chatham House have worked with eight experts to produce this collection of essays examining four contested themes in contemporary policymaking on deterrence. The themes – each explored by two of the authors in separate chapters – are set out below.
Contested themes in the examination of deterrence policies
Underlying assumptions of deterrence
- What could constitute potential drivers of arms race, and what steps can prevent escalation while keeping the status quo?
- Does the concept of ‘rationality’ still hold?
- How do different regions conceptualize deterrence?
Extended deterrence
- What are the options for strengthening nuclear deterrence in responding to the new security challenges?
Emerging technologies
- What is the added deterrence value of emerging technologies?
- Does increased vulnerability of systems create more uncertainty; and would heightened uncertainty increase or undermine deterrence?
- How do emerging technologies challenge deterrence?
Blurring the lines between conventional and nuclear deterrence
- Is there a difference between conventional deterrence and nuclear deterrence?
- What does modern deterrence mean in today’s security environment?
Underlying assumptions of deterrence – chapters 2 and 3
In their respective essays, John Borrie and Maria Rost Rublee explore the underlying assumptions of nuclear deterrence, and the problems these present. Borrie focuses primarily on shortcomings of human rationality that have been brought to light by research disciplines such as psychology and economics – research that has disquieting implications for assumptions about rationality in crisis. Rublee focuses chiefly on the political assumptions that contribute to the destabilization of nuclear deterrence. Despite their different approaches, these two authors ultimately make the case that the dynamics at work now are not the same as those that operated during the Cold War, and that, as it currently stands, nuclear deterrence is disrupted and presents a higher risk than at any time since the depths of the Cold War.
Borrie argues that human preferences are frequently affected by emotions and hard-wired cognitive biases; and that, as a result, it is harder to predict how decision-makers will necessarily act in a nuclear crisis based on the assumption that they are rational in utilitarian terms.1 Borrie’s essay suggests that the way in which each potential aggressor receives and acts in response to messages intended to deter will be greatly informed by an outlook that has heuristics and blind spots, among other features.2 Simply put, we do not know whether a common rationality will hold to prevent nuclear weapon use in the future. This chimes with Rublee’s point about the role played by ‘imperfect information’: without a deep and comprehensive understanding of a potential adversary’s priorities, perceptions and strategies,3 miscalculation could lead a state to underestimate the likelihood of escalation and potential nuclear use by that adversary.
Borrie argues that there is a need for more openness among policymakers that nuclear deterrence may fail, whatever the elegance of rational theory, especially given how unintuitive probability is to human minds,4 the tendency to misjudge randomness and non-linearity,5 and the human bias towards considering unlikely events to be impossible events.6 This may be a danger to the sustainability of nuclear deterrence: as Rublee indicates, the likelihood of ‘limited’ nuclear use has increased7 – thus adding to the variables that disrupt overall stability and security.
Extended deterrence – chapters 4 and 5
Extended nuclear deterrence is also constructed differently today than during the Cold War. It takes different forms in every region.
In their respective essays, Cristina Varriale and Tanya Ogilvie-White assess the value and limitations of the US’s extended deterrence, with reference to the Korean peninsula (Varriale) and Australia (Ogilvie-White). Whereas Varriale calls for further consideration of the linkage between conventional and nuclear threats and risks on the Korean peninsula, Ogilvie-White argues for an alternative arms control regime in the Asia-Pacific region.
These two authors hold different views on the current importance and role of US extended nuclear deterrence, although this may be due to the different geopolitical contexts within which both authors examine the commitments. While Varriale argues that extended nuclear deterrence is a key feature of the security framework on the Korean peninsula, Ogilvie-White questions its credibility and reliability in the wider Asia-Pacific region. Varriale argues that current US extended deterrence commitments to South Korea are separate from the drivers of North Korea’s proliferation and the broader peace and security of the peninsula. Ogilvie-White makes the case that new arms race dynamics and rapid technological change are resulting in an erosion of the credibility of US extended nuclear and conventional deterrence. She argues that Australia should focus on its diplomatic capabilities to reduce risks and improve the region’s long-term outlook by spearheading new regional arms-control initiatives.
Emerging technologies – chapters 6 and 7
Current and future technological developments pose both opportunities and risks in the nuclear realm. Whereas some experts claim that emerging technologies will serve to strengthen existing deterrence assumptions, others believe that emerging technologies bring the risk of undermining and weakening nuclear deterrence.
In their respective essays, both Andrew Futter and Jamie Shea consider that emerging technologies present challenges to the traditional way of approaching nuclear deterrence, and the context within which the nuclear community thinks about deterrence.
Shea argues that NATO allies even have the capacity to use cyber or electronic activity against each other. (Indeed, classified documents leaked by former US National Security Agency consultant Edward Snowden in 2013 gave apparent evidence of, inter alia, the extent to which the US had already spied on its allies, including through the tapping of European leaders’ phones.8) Futter examines the use of cyber means against an adversary, and draws attention to the ‘grey area’ that these technologies are creating between nuclear and conventional weapons. He suggests, too, that emerging technologies could perhaps even replace nuclear weapons for certain deterrence functions. Shea argues that deterrence can be enhanced in ways that allow it to play a more positive role – outlining five areas in which this might happen, and detailing how the development of these areas is ultimately the task of policymakers seeking to counter hybrid warfare and ‘grey zone’ operations in the years ahead. The five areas are: declaratory policy; developing operational response capabilities to be used flexibly and proportionately; enhancing the resilience of critical infrastructure and networks; better anticipating the impact of disruptive technologies; and achieving agreement on norms and regulations at an earlier stage.
Blurring the lines between conventional and nuclear weapons – chapters 8 and 9
There are signs that the possible (or threatened) use of nuclear weapons could become the ‘new normal’ for nuclear deterrence postures, as countries begin to blur the lines between their conventional and nuclear weapons.
In their respective essays on this theme, Peter Watkins and Christine Parthemore discuss the relevance of separating conventional and nuclear weapons. Both authors are of the view that two major shifts are currently happening as a product of technological and political evolutions. First, the potential use of low-yield – or relatively lower-yield – nuclear options by the US and Russia is changing perceptions of the way future conflicts may be carried out, and lowering the threshold for nuclear use by bringing these low-yield options to form part of war-fighting strategy.
The second type of blurring lies in nuclear responses to – and therefore deterrence of – non-nuclear attacks. Watkins outlines Russia’s military doctrine of ‘new generation warfare’, which sets forth a type of warfare capitalizing on a set of elements including indirect action, informational campaigns and private military organizations backed by sophisticated conventional and nuclear capabilities,9 which deliberately blurs the lines between the use of unconventional means such as cyber, conventional forces and nuclear forces. In parallel, the author also points out the explicit statement made by the US administration in its 2018 NPR that ‘deterring nuclear attack is not the sole purpose of nuclear weapons’, and that nuclear weapons could be used to deter ‘significant non-nuclear attacks’10 – thus implying that nuclear weapons could be used in response to cyber operations. Parthemore makes similar observations with regard to the NPR, and draws parallels between the latter and India’s deterrence doctrine of leaving open the possibility of nuclear retaliation for major chemical or biological weapon attacks.11
1 For example, as shown by the Wason Selection Task. See Borrie, J. and Thornton, A. (2008), The Value of Diversity in Multilateral Disarmament Work, UNIDIR, p. 32, https://www.unidir.org/sites/default/files/publication/pdfs/the-value-of-diversity-in-multilateral-disarmament-work-344.pdf (accessed 27 Nov. 2019).
2 For a fuller discussion, see also Mazarr, M. J., Chan, A., Demus, A., Frederick, B., Nader, A., Pezard, S., Thompson, J. A. and Treyger, E. (2018), What Deters and Why: Exploring Requirements for Effective Deterrence of Interstate Aggression, RAND Corporation, pp. 7–10, https://www.rand.org/content/dam/rand/pubs/research_reports/RR2400/RR2451/RAND_RR2451.pdf (accessed 27 Nov. 2019).
3 Peters, R., Anderson, J. and Menke, H. (2018), ‘Deterrence in the 21st Century: Integrating Nuclear and Conventional Force’, Strategic Studies Quarterly, 12(4), pp. 15–43, https://www.airuniversity.af.edu/Portals/10/SSQ/documents/Volume-12_Issue-4/Menke.pdf (accessed 27 Nov. 2019).
4 See Box 1 on ‘quantifying the probability of nuclear weapon detonations in populated areas’ in Borrie, J. (2014), Risk, ‘normal accidents’, and nuclear weapons, UNIDIR/ILPI, p. 2., https://unidir.org/sites/default/files/publication/pdfs/a-limit-to-safety-en-618.pdf (accessed 27 Nov. 2019).
5 See Taleb, N. N. (2004), Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets, 2nd edn, London: Penguin, p. 38.
6 Borrie and Thornton (2008), The Value of Diversity in Multilateral Disarmament Work, p. 43.
7 There is growing evidence that some countries are planning hybrid strategies with options for limited nuclear use. See Peters, Anderson and Menke (2018), ‘Deterrence in the 21st Century: Integrating Nuclear and Conventional Force’.
8 For a summary, see Wickett, X. (2018), Transatlantic Relations: Converging or Diverging?, Chatham House Report, London: Royal Institute of International Affairs, p. 22, https://www.chathamhouse.org/sites/default/files/publications/research/2018-01-18-transatlantic-relations-
converging-diverging-wickett-final.pdf (accessed 6 Feb. 2020).
9 Adamsky, D. (2018), ‘From Moscow with coercion: Russian deterrence theory and strategic culture’, Journal of Strategic Studies, 41(1–2), pp. 40 and 47, doi:10.1080/01402390.2017.1347872 (accessed 27 Nov. 2019).
10 Office of the Secretary of Defense (2018), Nuclear Posture Review, US Department of Defense, p. 21, https://media.defense.gov/2018/feb/02/2001872886/-1/-1/1/2018-nuclear-posture-review-final-report.pdf (accessed 14 Aug. 2019).
11 Chari, P. R. (2014), ‘India’s Nuclear Doctrine: Stirrings of Change’, Carnegie Endowment for International Peace, 4 June 2014, https://carnegieendowment.org/2014/06/04/india-s-nuclear-doctrine-stirrings-of-change-pub-55789 (accessed 27 Nov. 2019).