Trident renewal: Strategic utility and trade-offs must be made explicit

This work explores the challenges facing UK defence in the run-up and aftermath of the 2015 Strategic Defence and Security Review.

About the research

Nuclear weapons have been a cornerstone of British defence, security and foreign policy since the early 1950s. However, the UK’s fleet of nuclear submarines is coming to the end of its service life, and, if it is to be renewed, the manufacture of replacements must begin soon.

The UK government will make the ‘main gate’ decision to proceed with the manufacture of a Trident replacement – effectively committing the UK to nuclear weapons status for the foreseeable future – in 2016. At the same time, the rise of the Scottish National Party and the election of Jeremy Corbyn to the leadership of the Labour Party have introduced powerful anti-nuclear voices to mainstream British politics. In consequence, the decision on whether to retain the UK’s nuclear status is perhaps more open and contested than it has been for many years. Arguments for and against Trident renewal centre around four main areas of debate: first, the strategic utility, or not, of nuclear weapons possession; second, their role in sustaining UK status and influence in the international realm; third, the moral dilemmas of nuclear weapons possession; and finally, the effective uses of resources during a prolonged period of government austerity.

Image by bodgerbrooks [CC BY-SA 2.0 (], via Wikimedia Commons

Policy implications

  • The current decision on Trident renewal comes at a time when the question of UK nuclear weapons possession is unusually open and contested, with implications and effects that will be generational in scope. The government should take this opportunity to encourage an open and serious public debate about the UK’s nuclear status.
  • Government needs to be clearer about the trade-offs involved in any decision to renew Trident, particularly regarding cuts to UK conventional military forces. Such assurances should go beyond boilerplate discussions of deterrence and insurance policies and focus on specific questions of utility and vulnerability, including lessons from the past and likely strategic futures.
  • The Trident decision relates to, and should feed into, wider debates about the UK’s global role, the risks and burdens it is willing to take on in the international arena, and the levers it has at its disposal to achieve these goals. Government should make these considerations explicit in the wider discussion around Trident renewal.
  • Multilateral nuclear disarmament is unlikely in the foreseeable future. The debate about nuclear disarmament in the UK should therefore take place with this in mind and on its own terms, rather than as an action dependent on global denuclearisation.

Key findings

  • The strategic utility of Trident hinges in part on a tension between the complexity and uncertainty of the current (and likely future) security environment.
  • Complexity arguably challenges the deterrence concept. The prevalence of non-state adversaries and transnational security threats raises difficult questions of who is to be deterred, or influenced, by nuclear weapons, how and to what end.
  • Uncertainty can reinforce arguments for nuclear weapons possession. It may be wrong to rule out a renewed significance for deterrence in the long term.
  • Nuclear weapons possession is viewed by many as a prerequisite for UK influence in the international arena. However, there may also be significant international moral and political capital for the UK in a conscious decision to abandon its nuclear weapons status, in the non-proliferation process and elsewhere.
  • The cost of retaining nuclear capability has become an increasingly important factor in the debate, as government austerity policies sharpen choices about public spending. This is particularly so given recent cuts to UK conventional forces.

Further information

In October 2015 Bristol University’s Global Insecurities Centre hosted a workshop to consider the challenges outlined in this brief and accompanying report.

The workshop was funded by the Economic and Social Research Council (ES/L001616/1) and co-hosted by the Universities of Bristol, Birmingham and King’s College London, as part of a series of expert events on the future of British defence.

The full report is freely available on the Global Insecurities Centre Website at: insecurities/workingpapers/

Contact the researchers

Professor Andrew Dorman,
King’s College London:

Professor David Dunn,
University of Birmingham:

Professor Timothy Edmunds
University of Bristol:


Professor Andrew Dorman, King’s College London; Professor David Dunn, University of Birmingham; Professor Timothy Edmunds, University of Bristol

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