Defending the Falklands: A role for nuclear weapons?

By Alex Calvo and Olivia Olsen:


Deep conventional cuts have put a question mark over the British defence posture in the South Atlantic. Although the steep deterioration in Argentine military capabilities means that the balance of power has not necessarily moved against London, the deterioration in expeditionary and amphibious capability has led to what some voices consider to be an excessive reliance on static defence. In other words: in Royal Air Force Mount Pleasant’s ability to resist while airborne reinforcements arrive. Since the UK retains her nuclear deterrent, it is only logical to ask ourselves whether it may also contribute to the successful defence of the Falklands. The purpose of this paper is to examine whether current nuclear doctrine allows for this.

The strategic and the tactical levels

There are two basic ways in which nuclear weapons may be employed in defence of the Falklands. First of all, at the strategic level, deterring Argentina by threatening her population centres in the event of an invasion. Second of all, at the tactical level, by attacking air and naval bases with low-yield warheads in such a case or right before it, pre-emptively.

The 2006 White Paper: a door open?

We shall begin our examination of British nuclear doctrine with the 2006 white paper titled ‘The Future of the United Kingdom’s Nuclear Deterrent’[i]. This document makes it clear that ‘we deliberately maintain ambiguity about precisely when, how and at what scale we would contemplate use of our nuclear deterrent. We will not simplify the calculations of a potential aggressor by defining more precisely the circumstances in which we might consider the use of our nuclear capabilities. Hence, we will not rule in or out the first use of nuclear weapons’. It is thus clear that there is no need to be attacked with atomic weapons first, in order to respond in kind. Needless to say, Argentina is not a nuclear-weapons state, although it has a certain ‘latent’ nuclear and missile capacity, and therefore a ‘no first use’ declaration by London would make any further discussion unnecessary.

Once this is understood, it is now necessary to examine under what conditions a conventional attack from a non-nuclear weapons state, either alone or in association with a nuclear weapons state, may be met with an atomic strike. The document is not that clear about this, since it contains no explicit statement saying whether the UK may employ nuclear weapons against a non-nuclear weapons state. However, its tone and some of its assertions seem to at least imply that the country’s nuclear-deterrent is basically, if not solely, aimed at other nuclear-weapons states, whether acting directly or by means of sponsored terrorist groups. We can see this in its section ‘The UK Approach to Nuclear Deterrence,’ listing ‘Five enduring principles’ underpinning ‘the UK’s approach to nuclear deterrence.’ These five principles clearly refer to other nuclear-weapons states, whether recognized or not by the treaty on the non-proliferation of nuclear weapons (NPT).

For example, the first is titled, ‘our focus is on preventing nuclear attack’ and states that, ‘The UK’s nuclear weapons are not designed for military use during conflict but instead to deter and prevent nuclear blackmail and acts of aggression against our vital interests that cannot be countered by other means.’ Although this clearly points out in the direction of other nuclear-weapons states, we should note the following:

a) Not being ‘designed’ does not mean not being able to be employed. The word ‘designed’ is ambiguous, probably intentionally so. It is likely that this is no accident, but rather a deliberate attempt at not ruling out any option. Actually, such ambiguity is built in British nuclear doctrine, as clearly stated in the third principle, discussed below.

b) The provision ‘that cannot be countered by other means’ stresses the strong link between conventional military capabilities and nuclear doctrine, a connection often missing in the debate on defence cuts. Politicians and the public should understand that the lower British conventional capabilities are, the lower the threshold for the use of nuclear weapons must be, if we are to retain the same level of commitment to our national security. The comparative approach may come in handy here; Moscow is unable and unwilling to cut down her tactical nuclear arsenal because her conventional military capabilities are insufficient to deter potential enemies, above all China. Only a successful conclusion of the current Russian military reforms, resulting in a modern, agile, conventional force, able to defeat the People’s Liberation Army (PLA) in the field, may pave the way to negotiations in this arena. Similarly, for the UK to rule out using tactical nuclear weapons against countries not possessing them (which, again, the 2006 paper does not do), would require a major upgrade in conventional military capabilities. The alternative, which we may call the ‘Russification of the Falklands’, that is just like Russia versus China resorting to non-conventional arms to cover one’s conventional weakness, would be to explicitly rely on tactical nuclear weapons in the defence of the Islands. This would entail a significant departure from the current British nuclear posture, going from ‘minimum’[ii] to ‘maximum deterrence’.

The third principle[iii] should also be read carefully and in its entirety: ‘we deliberately maintain ambiguity about precisely when, how and at what scale we would contemplate use of our nuclear deterrent. We will not simplify the calculations of a potential aggressor by defining more precisely the circumstances in which we might consider the use of our nuclear capabilities. Hence, we will not rule in or out the first use of nuclear weapons.’ This is quite self-explanatory, but we can perhaps look in some more detail at the last sentence. Not ruling out a first strike is an option which basically makes sense against non-nuclear-weapons states (or with a rudimentary, or solely tactical, nuclear capability).

Why? Because when faced with a country possessing a similar strategic nuclear capability, it does not really matter who is the first to employ it, since the end result is the same, the destruction of both powers, ‘Mutual Assured Destruction’ or MAD. When does it then matter whether or not to be ready to use them? When at war with powers not having them, or where the possibility of striking them with nuclear weapons may serve as a deterrent, either preventing an outbreak of hostilities or, at least in theory, the escalation of the conflict (also called ‘intra-conflict deterrence’).

Thus, while the British nuclear deterrent was not originally designed to deal with conventional aggression, and the UK doctrine mainly refers to dealing with nuclear threats or attacks, its documents do not rule out a first strike and more to the point do not provide any explicit assurance to non-nuclear weapons states.

The 2003 Defence Ministry White Paper and the UK policy aims

This is made even clearer in another key document, the 2003 Defence Ministry White Paper on ‘Delivering Security in a Changing World’,[iv] which, while noting that ‘The Government’s policy on nuclear weapons remains as set out in the SDR’, assigns a broad deterrent role to British nuclear forces and lists a number of ‘UK policy aims’ which include responsibility for overseas territories and economic and trade matters, ranging from the ‘free flow of natural resources’ to ‘overseas and foreign investment’. While not stating a direct link between each and every such aim and the nuclear forces, it provides a measure of ambiguity in not clearly defining which may merit the employment of the atomic deterrent. Some observers have noted that these very broad interests go beyond existential threats.[v]

The 2010 NSS and SDSR: confirming nuclear ambiguity

Two additional important documents appeared in 2010, partly dealing with nuclear weapons: the National Security Strategy (NSS)[vi] and the Strategic Defence and Security Review (SDSR).[vii]

The NSS does not specifically refer to the criteria for their employment, but the SDSR discusses this in a number of passages. It explains that ‘to respond to the low probability but very high impact risk of a large-scale military attack by another state, we will maintain our capacity to deter, including through the nuclear deterrent.’ It must be noted that this is not qualified by the assertion that such an attack must be nuclear, or even that the state carrying out should have that capability. This is later compensated, however, with a reference to the ‘need for a minimum effective nuclear deterrent as the ultimate means to deter the most extreme threats’, although a list of such threats is not provided, and therefore a conventional attack on the Falklands is not explicitly ruled out.

Thus, the SDSR confirms, rather than dispels, the traditional ambiguity on the scope of the British nuclear deterrent, its possible targets, and the kind of attacks it could respond to. The text says that ‘The UK has long been clear that we would only consider using our nuclear weapons in extreme circumstances of self-defence, including the defence of our NATO Allies, and we remain deliberately ambiguous about precisely when, how and at what scale we would contemplate their use’.

The negative use assurance and countries acting in concert with nuclear powers

The SDSR also contains, however, a so-called negative use assurance, stating that ‘We are now able to give an assurance that the UK will not use or threaten to use nuclear weapons against non-nuclear weapon states parties to the NPT. In giving this assurance, we emphasise the need for universal adherence to and compliance with the NPT, and note that this assurance would not apply to any state in material breach of those non-proliferation obligations.’ The question thus emerges of whether this assurance covers Argentina, a non-nuclear weapons state party to the NPT. At first sight it seems it would, but similar guarantees are usually interpreted as not covering countries acting in concert with nuclear-weapons states.[viii]

Which confirmed that the use or threat of use, of nuclear weapons is subject to the laws of armed conflict, and rejected the argument that such use would necessarily be unlawful’. Although ‘the threshold for the legitimate use of nuclear weapons is clearly a high one’ and the UK ‘would only consider using nuclear weapons in self-defence (including the defence of our NATO allies), and even then only in extreme circumstances’, British doctrine is based on the principle that ‘The legality of any such use would depend upon the circumstances and the application of the general rules of international law, including those regulating the use of force and the conduct of hostilities’.

That is, British doctrine considers that international law does not in itself make illegal employing nuclear weapons against non-nuclear weapons states. Rejecting an invasion of British territory would clearly fall within the confines of ‘self-defence.’ Even more so thanks to the reference to ‘our NATO allies’, since it would not seem logical to employ atomic weapons to defend foreign lands and not a British Overseas Territory.

Possible changes to nuclear targeting policy and arsenal to enhance deterrence

British nuclear weapons are currently strategic and not targeted at any country in particular.[ix] While changing these two factors is not strictly speaking necessary to guarantee an effective deterrent against Argentine aggression, two amendments may be advisable. First, publicly announcing that the country had become the pre-planned target for some of the missiles on board the submarine on patrol at any given time could send a powerful message to Buenos Aires, reducing the scope for miscalculations. Second, given the high threshold use for strategic weapons, it may be advisable to recover an explicitly tactical capability. Although strategic devices may be employed in a tactical role, the risk for miscalculations by would-be aggressors may be higher if the UK’s arsenal contains no specific tactical devices.

Conclusions: a role for nuclear weapons in the South Atlantic

Deep defence cuts and the loss of a significant portion of the British expeditionary capability have made the defence of the Falklands heavily reliant on Mount Pleasant and aerial reinforcement. While the military balance in the South Atlantic remains favourable, a purely conventional posture may no longer be sustainable. By analogy with Russia, it could be termed the ‘Russification’ of the Falklands. An examination of British nuclear doctrine has shown that, while originally designed to mainly counter non-conventional threats, it does not rule out reacting to conventional attacks not threatening the very existence of the United Kingdom. However, in order to make the nuclear deterrent more credible in the South Atlantic, and reduce the scope for another miscalculation, it may be advisable to amend targeting policy and recover a specific tactical capability.



Alex Calvo is a guest professor at the Law Department of Nagoya University (Japan). Olivia Olsen is a War Studies graduate from Wolverhampton University. You can follow Alex Calvo on Twitter @Alex_Calvo.


1 The Future of the United Kingdom’s Nuclear Deterrent, London, United Kingdom Ministry of Defence, December 2006, available at
[ii] A concept confirmed in the 2010 Strategic Defence and Security Review, which refers to ‘a minimum effective nuclear deterrent’ Securing Britain in an Age of Uncertainty: The Strategic Defence and Security Review, London, United Kingdom Government, October 2010, p. 12, available at
[iii] The Future of the United Kingdom’s Nuclear Deterrent, p. 18.
[iv] Delivering Security in a Changing World. Defence White Paper, London, United Kingdom Ministry of Defence, December 2003, available at
[v] Nick Ritchie, UK nuclear weapons policy: deconstructing ‘minimum deterrence’, British International Studies Association, 2011, p. 6, available at
[vi] A Strong Britain in an Age of Uncertainty: The National Security Strategy, London, United Kingdom Government, October 2010, available at
[vii] Securing Britain in an Age of Uncertainty: The Strategic Defence and Security Review, London, United Kingdom Government, October 2010, available at
[VIII] Martin Butcher, Otfried Nassauer and Stephen Young, Nuclear Futures. Western European options for nuclear risk reduction, BASIC-BITS Research Report 98.5, British-American Security Information Council and Berlin Information Center for Transatlantic Security, December 1998, p. 13, available at
[ix] ‘In a posture known as Continuous At Sea Deterrence (CASD), one submarine, armed with up to 16 Trident missiles and up to 48 warheads, is always on deterrent patrol 24 hours a day, 365 days a year. The notice to fire has been increased to several days since the Cold War ended and the missiles are not targeted at any country.’ ‘Fact Sheet 4: The Current System’ The Future of the United Kingdom’s Nuclear Deterrent, London, United Kingdom Ministry of Defence, December 2006, p. 1, available at

5 thoughts on “Defending the Falklands: A role for nuclear weapons?”

  1. There is no need to mention nuclear weapons. To imply that we threaten Argentina with nuclear weapons would give it the right to denounce any treaties and to improve Condor II to III and to produce their own nuclear weaponry. Argentina has all the technology it needs for this and it has had this technology for many years. The only thing holding back that country are the bad governments. Secondly if Argentina was to arm itself with nuclear weapons by necessity Chile and Brazil would need to have them too. It is a daft proposition and morally no nuclear nation ever should abuse its privilege and threaten a non nuclear nation with nuclear weapons.. period. We shouldn’t go here it is a daft proposition which could undermine the non nuclear policies which prevail in all South America. When Russia which guaranteed the integrity of Ukraine in return for Ukraine giving up its nuclear weapons, then threatened Ukraine with its own old nuclear weapons I felt that Putin was scum in every respect and regardless of what angle you looked at him. We should operate with dignity, never give up our nuclear weapons but also always use them in a morally correct manner. Those who honorably refrained from developing them or have given them up should be afforded the greatest respect for this.

  2. Your article fails to address what the Islanders think about the deployment of nuclear weapons in their home!! I think you will find that we would say No Thank You!!

  3. Whilst you may think this article is founded on facts it is only opinion. Islanders would not allow Nuclear weapons to be used and any threat or even hint of a nuclear threat by the UK against any Southern american state is a recipe not only for disaster but one in which you can kiss any treaty goodbye! The only defence of these islands is by conventional and diplomatic means. No one including the International Community and including most the Argentinians wants any form of conflict. The British do have a capability and I believe the land and Air defences would see of any potential risk. The Uk has a very high tech Military which is the envy of many a country. Hot air is not a threat.

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