Download PDF A nuclear-weapon system designed to guarantee the UK’s survival could hasten its political demise.

The decision to replace, like-for-like, the United Kingdom’s fleet of nuclear-armed submarines carrying Trident ballistic missiles was taken in March 2007 – before the financial crisis and the rise to power in Scotland of the Scottish National Party (SNP). Neither event was anticipated then. The recession and budgetary constraints that followed the banking collapses of 2008 had little effect on the project in its preparatory phase, when spending was modest. But the announcement of a referendum on Scotland’s independence, to be held in September 2014, threw a spanner into the works. The SNP pledged to evict nuclear submarines from their bases in the Clyde when Scotland attained the legal rights and powers of a sovereign state. Since there appeared to be no plausible alternative bases in England and Wales, a ‘yes’ vote in the referendum might have ended the UK’s long engagement with nuclear weapons.

In the event, Scotland’s voters rejected independence by a significant margin, 55%–45%. The UK Ministry of Defence concluded that the nuclear bases’ future had been secured. Then the unexpected happened again. The SNP experienced a surge in support after the referendum, creating expectations that the UK general election in May 2015 would result in a government reliant on cooperation between the Labour Party and the SNP, again jeopardising ‘Trident’ (as the nuclear-weapons programme is colloquially known in British politics, and as it will be referred to here).

Instead, the Conservative Party gained a decisive victory, giving it enough votes to drive Trident’s replacement through the House of Commons against any opposition, including that coming from the SNP’s extraordinarily large bloc of 56 (out of Scotland’s 59) seats in the new parliament. It is tempting for the Conservative government to assume that the decision due in 2016 on moving the project from preparation into full manufacture is now unproblematic.

That assumption would be premature. Despite the referendum’s defeat and the Conservative Party’s ascendancy, profound changes have occurred, and are still occurring, in the political entity that still calls itself the United Kingdom. Where does political – rather than strictly legal – authority over decision now reside in this state, and how may it be exercised effectively, legitimately and without deleterious effect? Can the Union survive without fundamental reform? These are the deep questions upon which the fate of Trident, among other vital matters, will ultimately rest.

The SNP would also be mistaken to believe that it could frustrate Trident’s replacement without political risk. It cannot pretend that conflict with a nuclear-armed Russia and broader shifts in international power structures are not happening and have no consequences for the party’s stances on Trident and NATO membership, or for its international reputation. Nor can the UK pretend that Trident’s replacement is only simplified by threats from the East and elsewhere, since they dramatise choices between spending on nuclear and conventional forces, and between meeting defence and other priorities, at a time of financial austerity. All actors in this drama face predicaments.

The nub of the matter is this: if, as seems likely, consents are given and contracts issued in 2016 for the Trident weapon system’s manufacture, the UK government will find itself driven to protect the decision’s irreversibility over the medium and long terms. It will be making commitments to live with Trident’s opportunity costs and, absent a revolution in Scottish attitudes, coerce political Scotland into accepting that the UK’s new nuclear submarines will be based there for their lifetime, come what may. If the government is not prepared to make those commitments, the latter affecting the United Kingdom’s chances of survival, it will have to revisit the alternatives, and soon.

Squeaky gates

Exceptionally in British nuclear history, the decision to renew Trident was taken after an open public debate, culminating in the House of Commons’ endorsement of the policy in March 2007.1 The preparatory phase – termed ‘Initial Gate’ by the Ministry of Defence – was approved by the government in May 2011 after a period of conceptual design.2 The more momentous decision on manufacturing – ‘Main Gate’ – was placed in 2016 for tactical reasons. When the Conservatives and Liberal Democrats negotiated their coalition after the 2010 general election, the Conservatives made two concessions to avoid trouble over Trident (its replacement having been opposed by the Liberal Democrats in 2007). The Main Gate decision would not be taken during the coalition government’s five-year term in office, and a Lib Dem minister was granted permission to conduct a study within the Cabinet Office on alternatives to Trident’s like-for-like replacement, on condition that the deterrent’s abandonment was not considered. In the event, the study was carried out without affecting the replacement policy.3

How the Main Gate decision will be taken in 2016 is unclear. The Conservative government may not consider itself obliged to honour the Labour government’s pledge in 2007 to submit Main Gate to a vote in Parliament. It will probably opt to make use of its majority of votes in the House of Commons, swelled by votes of a pro-Trident wing of the Labour Party, to encase such an important decision in parliamentary cement and avoid appearing to run away from further debate.

Tactical judgements will affect the Main Gate decision’s precise timing: whether to place it before or after the Scottish parliamentary elections in May 2016; and whether to bring it forward into late 2015 or early 2016, especially if the government chose to hold the referendum on membership of the European Union (EU) in 2016 rather than 2017, and wished to get Trident out of the way beforehand.

Economic squeeze

Economic concerns may also influence the decision’s timing and, more importantly, political and military attitudes towards the Trident replacement programme and its implementation. Whichever government took office in 2015 was obliged to conduct a Strategic Defence and Security Review (SDSR), the last one having been undertaken in 2010. Its completion is expected in November 2015. Among other things, the review will set out plans for spending on the armed forces and their equipment in coming years. It is taking place just as the Conservative government is acting on its election promise to reduce the UK’s enormous budgetary deficit and foreign borrowings by curbing public expenditure.

Having suffered cuts over several years, the UK’s defence budget would have fallen well below the NATO target for member states’ defence spending (2% of GDP) had the new Conservative government not committed extra resources to end the decline. It was responding partly to heavy American pressure, as expressed by President Barack Obama during his meeting with Prime Minister David Cameron at the June 2015 G7 Summit in Bavaria.4 On 8 July, George Osborne, Chancellor of the Exchequer (as the British finance minister is known), announced that the government would meet the NATO target after all.5 However, pressures within the defence budget were eased only to a degree, since spending on military pensions, peacekeeping and some other items were brought into it for the first time. More significantly, the government announced that defence spending would increase by 0.5% per annum in real terms during its term in office, halting the real decline.6

The large rise in spending on the Trident replacement project from 2016 onwards is inconvenient for the government. Although its costs are contested (the government forecasted a capital investment of £10–15 billion at the programme’s launch in 2007), the project is expected to absorb between one-quarter and one-third of the UK’s defence procurement budget if it is implemented according to plan.7 Trident’s opportunity costs are obvious amidst pressures to invest in many other kinds of military equipment and infrastructure, including novel technologies sought in response to terrorism, cyber attack and emerging threats in the Middle East and elsewhere, while maintaining troop levels and meeting demands for adequate salaries and conditions of service.

Actual defence spending will be sensitive to future GDP growth rates, tax revenues and levels of borrowing, all of which will be influenced by international economic conditions that are becoming more fragile at the time of writing. For Trident’s supporters, the danger has long been that senior figures in the armed services would turn their guns on the project, encouraging debate, largely avoided in 2007, on the nuclear force’s military utility. The armed forces had been made more vulnerable to Trident’s cost by the present Chancellor’s decision to fund the replacement project out of the defence budget, ending the practice of paying for the UK’s nuclear weapons out of special funds. Giving priority to spending on Trident also privileges the navy, since the army and air force no longer have nuclear weapons in their armouries.

Even without the recent increase in defence spending, it was always unlikely that a Conservative government would allow the Trident replacement programme to be derailed for economic reasons or to make way for investments in conventional defence, however badly they might be needed. Desiring to preserve ‘continuous-at-sea-deterrence’ (CASD), it has also dismissed proposals to reduce the number of nuclear-armed submarines from four to three.8 The Conservative Party’s support for the deterrent is deep-seated, reflecting the political elite’s attachment of high value to Trident as a pillar of the transatlantic relationship and symbol of the UK’s desire to remain a great power with global reach. Furthermore, active modernisation and deployment of nuclear weapons by Russia, great-power rivalry in Asia and setbacks in arms control hardly provide the environment in which a government could happily contemplate abandonment of the UK’s longstanding deterrent and role in NATO’s nuclear defence.

The Scottish question

The UK government will still have to find a way past unremitting Scottish opposition to its plans. The UK’s nuclear force relies on two bases in Scotland. Nuclear warheads are stored and loaded onto missiles at Coulport on Loch Long. The fleet headquarters is at Faslane in nearby Gareloch. These sea lochs (fjords) open into the Firth of Clyde, which runs north–south, between the mainland to the east and the islands of Bute and Arran and the Mull of Kintyre to the west, before reaching the open Atlantic off the north coast of Ireland. Faslane is just 30 miles from Glasgow, Scotland’s largest city.

Opposition in Scotland to nuclear deterrence and the basing of the UK’s main nuclear force in the Clyde has a long history in civil society. Rooted in moral objection and perceptions of imperial imposition, it played a significant part in the SNP’s rise. For most of the time, the UK government and main political parties assumed that Scottish objections could be safely and justifiably ignored. Safely, because the SNP was regarded – until very recently – as a fringe party that would never gain high office. Justifiably, because Scotland was an integral part of the United Kingdom whose parliament in Westminster was sovereign across the entire territory and whose political and military elite alone possessed the experience and expertise to make appropriate decisions. The concentration of power of decision in London did not change when the Scotland Act of 1998 re-established the Scottish Parliament and granted it authority over certain fields of policy.9 Defence and foreign policy were ‘reserved’ to London with decision on nuclear matters ring-fenced to shield it from interference.10

The vote was treated as irrelevant in London

The Scottish Parliament in Edinburgh therefore played no part in the March 2007 decision to replace Trident. Upon winning the largest number of seats in the May 2007 Scottish election, the SNP-led minority government exercised its constitutional right to hold a debate on Trident in the Scottish Parliament, resulting in a decisive vote against the replacement policy.11 The vote was treated as irrelevant in London.

Furthermore, Trident’s replacement was promoted by a Labour government in 2007 when there were 40 Scottish Labour MPs in the House of Commons, some of whom held prominent positions in prime minister Tony Blair’s cabinet (notably Gordon Brown, chancellor of the exchequer, Des Browne, secretary of state for defence and John Reid, home secretary). Although 15 Scottish Labour MPs voted against the policy, the government was able to claim that Scottish interests were properly represented in London, and that the decision bore democratic legitimacy as well as constitutional legality.

Contrast this with the situation in 2016 when the decision on Main Gate is due. The UK government’s stance would be agreed by a cabinet that had no Scottish members other than David Mundell, the single Conservative MP elected to a Scottish seat in the 2015 general election, whom Prime Minister Cameron appointed Secretary of State for Scotland in the absence of a credible alternative.12 Put to a vote in the House of Commons, the government could now muster only two Scottish votes, at most, in favour of Trident’s replacement – one Conservative and one Liberal Democrat (possibly), the single Scottish Labour MP having already stated that he would vote against it.13 All other 56 Scottish seats in Westminster are now held by SNP MPs that will vote en bloc against the decision.

The Conservative Party has 330 out of 650 seats in the House of Commons, giving it a clear if slight majority. The SNP therefore has no chance of thwarting the replacement policy in Westminster if, as is probable, the Conservative Party remains united on the issue and is joined in the voting lobbies by a number of Labour MPs. As night follows day, a decision to proceed with Main Gate would trigger a debate in the Scottish Parliament resulting in an even more emphatic vote against the policy than in 2007, especially if the vote were taken after the May 2016 Scottish election when the SNP’s hold over the Parliament is expected to increase (the anti-Trident Scottish Green Party may also gain seats).14 It is also possible that the Scottish Labour Party, never enthusiastic about Trident, will vote against replacement in its effort to recover popularity after being crushed in the 2015 UK general election.

As before, the UK government could assert the legality of a decision to proceed with Trident’s replacement, especially if buttressed by the UK Parliament’s endorsement. Scotland is part of the United Kingdom, the Westminster Parliament is sovereign, and defence and foreign policy is reserved to London. As such, the government retains the full legal right to ignore the Scottish electorate and Parliament’s objections. However, it would have a tougher time asserting the decision’s political and democratic legitimacy. How could a policy, on a matter of special interest to Scotland, be considered legitimate when it has been voted against by close to 96% (possibly more) of Scottish MPs in the UK Parliament, and by a large majority of Members of the Scottish Parliament?

By pressing ahead regardless, the UK government would feed the Scottish narrative about England’s imperial imposition. Nevertheless, the Scottish government would be quite powerless to react so long as Scotland remained part of the UK. It could not prevent the Ministry of Defence’s issue of contracts to manufacturers of the submarines, reactors, warheads and other hardware.15 Through its devolved authority over planning, policing and emergency services, the Scottish Parliament has powers in principle to disrupt operation of Trident and its Scottish bases, powers that the Scottish government has been loath to use hitherto. It has feared London’s – and Washington’s – strong retaliation backed by accusations that it was acting ultra vires.

This said, no SNP-led Scottish government could turn a blind eye to London’s decision in 2016 to proceed with Trident’s replacement as if Scottish opinion were irrelevant. At the very least, the Scottish government can be expected to inform the UK government that nuclear weapons would be removed from Scotland when independence had been achieved, and that an independent Scotland would not accept any financial liability arising from the cancellation of contracts or cost of relocation.

Another Scottish referendum?

The SNP remains committed to the establishment, by democratic means, of a sovereign Scottish state outside the United Kingdom. However, the circumstances under which another independence referendum could and would be called remain uncertain, as does its outcome.

Two opinions are commonly expressed. One is that Scotland’s independence is inevitable – only its timing is uncertain. Centrifugal forces remain strong in British politics, and the UK’s metropolitan power structures and governmental system are too entrenched to allow the innovations that might revitalise the Union. Furthermore, the UK’s disintegration is now being driven by English as much as Scottish assertions of self-interest. The former prime minister Gordon Brown wrote recently, when reacting to a suggestion that Scotland would display the same diminishing interest in independence as Québec, that

there is a big difference [between post-referendum Québec and Scotland]: whereas the rest of Canada has consistently stood as one to keep Québec in, it is London’s equivocation over Scotland that is becoming the greater risk to the UK … While Scotland has not yet written off Britain, the Conservatives are beginning to write off Scotland.16

The other opinion is that Scotland’s independence may happen – and happen soon – but that it is not inevitable. Scotland’s citizens may come to prefer the greater autonomy within the UK that is currently under negotiation to independence and its perceived risks. Innovation in the UK’s institutions of government might also be greater than anticipated, driven partly by English regions’ demands for a lessening of London’s political and economic grip. The SNP itself is being notably cautious. Nicola Sturgeon, the First Minister of Scotland, has spoken of another referendum being justified only following ‘material changes’ in circumstance.17 There has also been talk of a referendum depending on ‘the will of the people’ rather than the choice of politicians.18 In practice, this means that Scotland’s political leaders will take their cue from opinion polls. They will only call another referendum when polls indicate that a majority of voters favours independence.19

A decision in 2016 to proceed with Trident’s manufacture could be cited as a material change. Nevertheless, it is unlikely that this decision would alone be regarded as sufficient to trigger a referendum. That would require some combination of material changes, among them economic policies that unduly damaged Scottish interests; London’s failure to deliver on promises made in the 2014 referendum’s last days and the subsequent Smith Commission’s proposals on further devolution; and an outcome of the referendum on EU membership that pulled Scotland out of the EU against its voters’ wishes.

Concerning the EU referendum, the Conservative Party promised that an ‘in–out’ referendum on EU membership would be held before the end of 2017 if it won the 2015 general election. It now has to deliver on that promise, and on Cameron’s commitment to renegotiate the UK’s relationship with the EU prior to deciding on his party’s stance in the referendum. For Cameron, persuading the 27 other EU member states to play ball, avoiding serious splits within the Conservative Party, placating the City of London and business interests and ultimately winning the referendum will be enormously challenging. These tasks will be much more preoccupying and dangerous to his reputation than Trident’s replacement.

The results of Cameron’s negotiations and the referendum cannot be predicted. Sturgeon has already claimed that the UK government would not have the legal right to withdraw Britain from the EU without the formal consent of the UK’s three other nations. Denied a veto (as she inevitably would be), she could cite withdrawal from the EU – and Main Gate among other developments – as rightful causes for another referendum. She cannot assume, however, that the Scottish electorate’s support for EU membership will be rock solid when the referendum is held. Her party faces difficult judgements on whether to support changes sought by Cameron, on which the Scottish government may not be consulted, and on how hard to press for continued EU membership.

Locking the gate

As the Main Gate decision approaches, the UK government will have to reckon with the real possibility that Scotland would gain independence within the new Trident system’s lifetime – perhaps before manufacture is completed – if it decided to press ahead with the project. Tens of billions of pounds might be spent on a weapon system rendered inoperable by politics.20 Prior to the decision, would the Treasury conduct a risk analysis? If allowed to do so by Downing Street, it would have to assess the probability of the rest of the UK being able or unable to use Faslane and Coulport if Scotland became a sovereign state, and to counsel accordingly.21

Whether Trident’s deployment out of the Scottish bases would, in reality, cease after independence was a question often asked in the run-up to the November 2014 referendum. The Scottish government’s answer was an emphatic yes: the bases would be converted to conventional military use when Trident had been removed. However, it said little about how the nuclear weapons would be removed, at what cost and under which transitional arrangements. Few believed its assertion that the weapons would be removed within two years of independence being attained. A more plausible scenario involved agreement on allowing the existing fleet to operate out of Faslane and Coulport until obsolescence in the late 2020s, with access denied to the new submarines and their armaments thereafter.22

The UK government, for its part, refused to engage in any public discussion of issues relating to Trident during the referendum debate. There was not even any contingency planning. The Ministry of Defence banked on the referendum being defeated. It shared the common belief that the independence movement would be so wounded by defeat that the Union’s survival, and Faslane and Coulport’s availability, could be taken for granted thereafter.

The UK and Scottish governments both understood that Trident’s future in Scotland would depend on political and economic bargains struck during negotiations that would have followed a ‘yes’ vote in 2014. Those negotiations would have been held before the Main Gate decision had been taken. The political context would have been very different to that pertaining in 2016, since the decision would have depended on the outcome of, in effect, interstate negotiations answerable to freshly constituted parliaments at Holyrood and Westminster. Similar interstate negotiations would presumably follow a ‘yes’ vote in a future Scottish referendum, except that they would then be occurring after the Main Gate decision and the ‘escalation of commitment’ that it entailed.23

Trident’s advocates may anticipate that the replacement policy’s deeper entrenchment after Main Gate would change both London and Edinburgh’s negotiating calculus, especially if new submarines had already entered service at Faslane and Coulport by the time of the next referendum. Since shifting tack on Trident would have become extremely difficult and costly, the government in London would feel impelled to exact a very high price for Trident’s removal. Indeed, its stay in Scotland might become a precondition for negotiation of any kind. The government in Edinburgh would then be faced with a starker choice: whether to concede to the nuclear navy’s continued use of Coulport and Faslane in return for concessions on other economic and other issues, or to accept the penalties attached to Trident’s banishment. George Osborne’s announcement on 31 August 2015 that £500 million would be lavished on Faslane, increasing employment there, signals that the the government is preparing to offer juicy carrots and wield big sticks to compel acceptance.24

Policymakers in London might imagine that popular opinion in Scotland would prove malleable when presented with this choice. They cannot count on this happening. So totemic is Trident’s removal in Scottish politics that a decision to grant permanence to the siting of nuclear weapons in Scotland would be regarded as the U-turn of all U-turns, risking division within the SNP and Scottish government and threatening them with a fundamental loss of public trust. Furthermore, Scottish intransigence would probably be increased by a decision to enforce the Main Gate decision in 2016 in defiance of the Scottish government and Parliament.

There is an alternative to imposition if the new system must be operated out of Scottish bases. It is for London to attain the support of the Scottish people for Trident’s continued presence in the Clyde by fostering and winning a debate within Scotland prior to the Main Gate decision. Such a debate has never been attempted. Yet the Scottish referendum revealed the SNP’s vulnerability when discussions turned to defence policy, except on Trident where it retained the upper hand partly because of the UK government’s refusal to engage on the matter. It would be surprising if the UK government, aided by sections of the media and the Conservative Party in Scotland, desisted from attacking the SNP’s stance on nuclear weapons, hoping that the SNP would prove vulnerable on this issue amidst so much anxiety about the deterioration in international security. Election of the anti-Trident Jeremy Corbyn to leadership of the Labour Party (which seemed likely at the time this article went to press) would tempt the government to extend the attack to all of the deterrent’s opponents, so as to drive division within the Labour Party. However, it might find itself vulnerable to the argument that huge outlays on a weapon system designed to meet Cold War challenges represented an inappropriate use of resources when spending on so much else was being cut.

The slight evidence from opinion polls suggests that opposition to Trident in Scotland may be less extensive than is usually assumed, and may diminish with distance from Glasgow and the bases.25 Attitudes might shift if, prior to Main Gate, the Scottish people were allowed by both UK and Scottish governments to have an open and well-informed debate on the merits and demerits of British policies on nuclear deterrence, including the nuclear force’s basing in Scotland. There appears to be no appetite in London for allowing this to happen. Time is perceived to be running out; launching a debate in Scotland would give it an inappropriate role in the Main Gate decision; and the political risks of fomenting opposition, in England as well as Scotland, would probably be considered too great. Opposition to Trident’s renewal is not confined to the SNP or Scotland.26

There is another question. Would the Ministry of Defence and nuclear navy enjoy operating the submarine force out of Faslane and Coulport if Scotland became a sovereign state and yielded to pressure to keep the bases open? No. Besides the usual issues that arise when running bases on foreign soil, Loch Long and the Gareloch would become Scotland’s internal waters, and the Firth of Clyde its territorial waters, under the Law of the Sea’s standard definitions. It is unlikely that a sovereign Scottish state would concede to the passage of nuclear submarines through these waters without close consultation and cooperation on matters concerning their protection and safety. Would the deterrent’s independence, and availability in all circumstances, be assured? What kind of treaty would be required to govern the two states’ nuclear relations? Could a sovereign Scottish state accept having no say whatsoever over use of a nuclear force based within 30 miles of Scotland’s largest city? Could it happily accede to part of its territory being declared a ‘sovereign base area’ over which the rest of the UK would retain sovereignty, from which the nuclear force could operate as if there had been no change in political circumstances? Could London trust Edinburgh to intervene if protesters frustrated Trident’s operation in any way?

Back to the alternatives

The UK government has four options for circumventing or overcoming Scotland’s opposition to its Trident replacement policy, none of which it probably considers palatable.

Firstly, it could abandon plans to maintain the British nuclear deterrent. This is least likely to happen, so great (outside Scotland) is the prestige value ascribed to nuclear weapons and the stigma attached to unilateral disarmament, and amidst worries about negative trends in international security.27 There is unlikely to be any departure from the UK government’s traditional assertion that the UK’s nuclear disarmament is contingent on global nuclear disarmament achieved through multilateral processes.

Secondly, the UK could adopt a nuclear-weapons system that did not rely on large naval bases and associated infrastructures. The alternatives have been studied on several occasions, always with the same conclusion: they would be militarily inferior, cost savings would be insufficient to justify the shift and they would present fresh technological challenges. The option of air-launched missiles would also return operational responsibility for the deterrent to the Royal Air Force, where it would not be welcome, and raise fresh basing issues.

Thirdly, bases equivalent to Faslane and Coulport could be established in England or Wales. The common assumption, inside and outside the Ministry of Defence, has been that finding appropriate geographical locations, gaining political consent for their development and financing the move would not be possible. Even if it were, reaching political agreement on a site would take too long. A study published shortly before the 2014 referendum suggested that the obstacles to opening new bases might have been exaggerated.28 It did not shift opinion. The UK government has also been adamant that operating the British nuclear force out of French or American bases will not be considered. Sovereignty of decision over the force’s deployment and use would be lost, and solutions would have to be found to numerous logistical, operational and political complications even if the host country were willing to provide sanctuary. This said, operating out of King’s Bay in Georgia would make some sense, given that the UK’s submarines already routinely visit the base when loading up with Trident missiles.

Fourthly, the UK government could reopen the question of the current Trident system’s operating lifetime. In early 2007, a group of eminent American experts, led by Richard Garwin, encouraged the Labour government of the time to work towards a lifetime of 45 years (the US standard) rather than the 30 years planned for the British submarines.29 Their proposal was rejected on contested grounds that the British and American systems were different in design and the American Trident fleet’s greater size made it more resilient to technological malfunction. If it were technically feasible, life extension would be attractive today insofar as it would relieve pressure on the defence budget; allow the government to wait and see how needs evolved; and create time in which to consolidate the Union and see off the Scottish challenge. However, the political and economic circumstances might be even less propitious in ten or 15 years’ time. The government would also worry about a loss of momentum, and the cost and difficulty of keeping the submarine yards ticking over in the meantime.

Each of the above options would require the UK government to reopen the national debate, as would any attempt to foster and win a debate on Trident’s replacement in Scotland. The government’s fifth option is to plough ahead regardless, using its majority in the UK Parliament to enforce the Main Gate decision.

A question of survival

The decision to replace the UK’s Trident force was taken in 2007. It is inconceivable that the same decision could be arrived at today through the same political process. The strategic case for the UK’s retention of a nuclear deterrent has not weakened. However, the UK’s internal politics and economic circumstances have changed utterly. This United Kingdom might not even exist in ten, 20 or 30 years’ time.

Although legal authority over defence and foreign policy remains in London, a decision to operate the nuclear submarines out of their current bases in Scotland could not have been contemplated today without Scottish consent, especially as expressed through the Scottish Parliament. Despite the Scottish electorate’s recent rejection of independence and the UK Parliament’s continuing formal supremacy, Scotland has become a democratic polity in its own right with expectations that it will have a say on issues of vital interest, now including reserved issues. The Scottish Parliament lies at the heart of that polity. A decision in 2016 to proceed with Trident’s manufacture that is supported by at most two of the 59 Scottish MPs in the Westminster parliament, and that is emphatically rejected by the Scottish Parliament, would be regarded as illegitimate in Scotland.

The replacement policy chosen in 2007 is ill adapted to new political and economic circumstances, and may be unsustainable as a result. What should now happen is that the cases for the deterrent’s renewal, for the Trident system’s retention or abandonment, and for the continued use of Faslane and Coulport are reopened to public debate in Scotland as well as in London. On an issue of such political, economic and moral gravity, the policy followed needs to be credible, carry legitimacy and be appropriate to the times. The debate is unlikely to be reopened, however, because the replacement project is inflexible and has already acquired momentum; its supporters fear losing control over the policy; allowing the Scottish Parliament a say would be regarded as unconstitutional; neither the Conservative Party (dominant in England) nor the SNP (dominant in Scotland) would be willing to concede ground on a totemic issue; and policymaking elites in London regard elites in Scotland as having neither the competence nor the experience required to make judgements on such essential matters. Furthermore, the governments in London and Edinburgh have too many other fish to fry on the economy, social welfare and management of the EU referendum to welcome an extensive debate on Trident.

No one can say whether the United Kingdom will hang together or fall apart. The possibility that Scotland will become a sovereign state cannot, however, be denied. Odds of 50/50 that this will take place before 2030 seem reasonable. Since the first new submarine is planned to enter service in 2028, Scotland’s independence could become a reality during the construction phase, let alone sometime after deployment.

As a result, a decision in 2016 to press ahead with the nuclear-weapons system’s manufacture would inescapably be a gamble. It would probably be regarded in London as a safe gamble – not because there is huge confidence in the Union’s survival, but because there is disbelief within London’s political and military elites that a newly independent Scotland could act out its promise to evict Trident when push came to shove. In this view, Scotland would surely be impelled to succumb to pressure and concede the nuclear force’s stay in the Clyde, especially if it wished to gain entry to NATO, since it would need to establish favourable economic and political relations with the rest of the UK, and with the United States and other powerful actors. When the costs of eviction became apparent, the Scottish people would see sense, and the Scottish government would come round to the idea of keeping Trident to strengthen a weak hand in negotiations.

This might happen, but no one should assume that it would. Reneging on the long-standing commitment to remove nuclear weapons from Scotland would be regarded as an act of betrayal by many supporters of independence unless some international crisis had brought a dramatic change of attitude towards deterrence in the meantime. The possibility that Scotland will become a sovereign state should therefore inform the decision on Main Gate, rather than being dismissed.

World views

An ironic distinction between the nuclear situations arising from the Soviet Union’s actual and the UK’s potential break-up deserves notice. In the early 1990s, the great objective – including the UK and US governments’ objective – was to remove, as rapidly as possible, strategic nuclear weapons from Belarus, Kazakhstan and Ukraine prior to their attaining statehood and to ensure that they renounced rights to acquire nuclear forces by joining the Nuclear Non-Proliferation Treaty (NPT) as non-nuclear-weapons states. The Russian Federation was alone entitled to retain its nuclear deterrent and the legal standing of a nuclear-weapons state under the treaty. In contrast, every signal coming from London, Paris and Washington during the 2014 referendum suggested that, in the event of the UK’s break-up, the great objective would be to avoid the removal of nuclear weapons from Scotland, and certainly to avoid their rapid removal, thereby enabling the rest of the UK to stay in the nuclear game whilst ensuring that Scotland also joined the NPT as a non-nuclear-weapons state.

The situations are different in two particular respects: Scotland is not regarded as a proliferation risk, having no imaginable desire to arm itself with nuclear weapons; and the Russian Federation, unlike the rest of the UK, could dispense with the weapons located in Belarus, Kazakhstan and Ukraine having plenty – including the entire submarine fleet at Severomorsk – based on its own sovereign territory. England lacks this capacity. Following Scotland’s independence, the rest of the UK would find itself, uniquely among nuclear-armed states, striving to base its entire nuclear force on the territory of a non-nuclear-weapons state, and one that opposed its presence there.

The UK’s allies may favour Trident’s like-for-like replacement. However, it would be difficult for them to give it strong, overt support if a contest developed between Scotland and the rest of the UK over basing rights. They might deny Scotland entry to NATO if it persisted with its anti-nuclear policy. However, coercing a non-nuclear-weapons state into providing bases for another state’s nuclear force – in effect pursuing a counter-disarmament policy – would not sit easily with the norms and rules of the international nuclear order, especially when nuclear non-proliferation and disarmament are being so strongly advocated. In addition, the Scottish referendum has already exposed the problems that the US and other democratic governments face when trying to reconcile the democratic rights of the Scottish nation with their interests in the UK’s survival. Those problems would become more acute if Scotland attained independence and sought to exercise its sovereign, democratic right to remove nuclear weapons from its territory.

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Ultimately, whether the UK should replace Trident is a question of marginal importance in world politics. Even within Europe, its nuclear force’s contribution to the balance of power and avoidance of war is questionable. Whether the UK hangs together as a state has much greater international significance.

The United Kingdom’s fate will be determined by much more than next year’s decision on Trident. But the nuclear force’s basing in the Clyde has long been a toxic issue in Scotland, breathing life into the idea of independence. A decision to press forward with the current replacement project, overriding Scottish opinion, would do further damage to the Union. Since the primary interest of foreign governments, including the US government, resides in the Union’s preservation, they should be advising the Conservative government to reconsider the current replacement policy, and to hold back from using its parliamentary majority to ram it through the House of Commons. The UK’s allies’ best outcome would probably combine the survival of the Union and of the nuclear deterrent, pointing towards development of an alternative to the submarine force or to its basing in Scotland (perhaps moving it to King’s Bay in Georgia), despite the hour being late.30

If the Scottish independence movement thinks Scotland’s best interests would be served by the UK Parliament’s peremptory decision to move ahead with Trident’s replacement, driving another nail into the Union’s coffin, it should think again. The Trident project’s deeper entrenchment, and the sharpening of Scottish antagonism towards it, would drive Edinburgh and London into a potentially nasty confrontation over the bases’ future after the Union’s break-up, at a time when there would be an urgent need to work together on state creation and re-creation. Such a confrontation would also act against the strong foreign interest in seeing Scotland and the rest of the UK settle quickly into a cooperative relationship.

I wrote the following in an article published by the Financial Times in March 2007.31 Not a single word needs changing as the Main Gate decision approaches:

When the Westminster parliament convenes to debate and vote on the government’s proposal, it should understand that the futures of Trident and the Union are now inextricably entwined and that Trident may become a significant agent of the UK’s disintegration if more care is not taken. The irony of ironies is that a system designed to guarantee the UK’s survival could hasten its political demise.


1 On 14 March 2007, 409 votes were cast in favour of, and 161 against, the government’s proposal to replace Trident. See Deborah Summers, Hélène Mulholland and Matthew Tempest, ‘MPs Vote to Renew Trident’, Guardian, 14 March 2007,

2 For a description of the activities involved in the project’s successive phases, see Claire Mills and Louisa Brooke-Holland, ‘The Trident Successor Programme: An Update’, Standard Note SN0625, House of Commons Library, London, 10 March 2015,

3 HM Government, ‘Trident Alternatives Review’, 16 July 2013, Nick Harvey, the Liberal Democrat minister given charge of the review and its main advocate, was removed from office before its completion.

4 ‘Obama Uses G7 to Press Cameron on Defence Spending’, Reuters, 7 June 2015,

5 ‘Budget 2015: UK to Meet NATO’s Defence Spending Target’, BBC News, 8 July 2015,

6 See Malcolm Chalmers, ‘Osborne’s Summer Surprise for Defence’, Royal United Services Institute (RUSI) briefing paper, London, July 2015,

7 See Malcolm Chalmers, ‘Towards the UK’s Nuclear Century’, RUSI Journal, vol. 158, no. 6, pp. 21–2; and Mills and Brooke-Holland, ‘The Trident Successor Programme: An Update’, pp. 21–3.

8 A fleet of four nuclear-armed submarines has long been regarded as the minimum necessary for practising CASD, whereby one nuclear-armed submarine is on patrol at any one time. Reduction to three might limit the UK’s ability to respond in a sudden crisis. Concerns have also been expressed that hastily sending a submarine to sea when none is deployed might escalate a crisis.

9 The previous Parliament of Scotland closed in 1707, after a more than 400-year history, when the Act of Union of that year created the Parliament of Great Britain located in London.

10 The 1998 Scotland Act grants the UK government ‘sole control over nuclear, biological and chemical weapons of mass destruction’. See The Defence Concordat agreed by Edinburgh and London also identifies as reserved matters ‘the installation, operation and decommissioning of any nuclear installation or device for the purposes of the armed forces of the Crown’. See

11 In June 2007, 71 Members of the Scottish Parliament (MSPs) voted against and 16 voted for Trident’s replacement, with 39 mainly Labour abstentions. The SNP’s 47 MSPs were joined in voting against the policy by 25 MSPs from Labour and other parties, the 16 votes in favour being cast by Conservative MSPs. See ‘MSPs Vote Against Trident Renewal’, BBC News, 14 June 2007,

12 Ministers are appointed to represent the interests of Scotland, Wales and Northern Ireland in the UK Cabinet, and to head the Scottish, Wales and Northern Ireland offices.

13 Andrew Whitaker, ‘Labour MP Ian Murray Breaks Ranks over Trident’, Scotsman, 14 April 2015,

14 The Scottish Parliament is elected through proportional representation rather than the UK Parliament’s first-past-the-post system. As a result, the Conservative, Labour and other opposition parties in Scotland have a greater chance of winning seats at Holyrood than at Westminster. The Scottish Parliament elected in 2011 contained 69 SNP, 37 Labour, 15 Conservative, five Liberal Democrat, two Green and one Independent MSPs, giving the SNP an overall majority in the 129-seat chamber. See ‘Summary of Seats by Party’, Scottish Parliament, 2011,

15 Little manufacture will take place in Scotland. The submarines, reactors and warheads will be manufactured in England at Barrow-in-Furness, Derby and Burghfield respectively. Not locating submarine manufacture in the Clyde’s shipyards long ago was a strategic mistake, since costs and benefits might have been weighed differently in Scotland if Trident had brought major employment to Glasgow.

16 Gordon Brown, ‘Britain’s Already Fragile Union is at Risk – Not from Scotland but its Own Government’, Guardian, 12 June 2015,

17 Sturgeon first said this in a BBC television debate involving Scottish party leaders on 8 April 2015.

18 Commenting on Alex Salmond’s appearance on BBC television on 26 July 2015, Matthew Cole reported an SNP spokesman saying that ‘The timing of any future referendum is a matter for the people of Scotland to decide – the people, not politicians, are in charge’. See ‘Second Independence Referendum “Inevitable” says Salmond’, BBC News, 26 July 2015,

19 Legal powers to call referendums in the UK reside in the UK Parliament. Consent for the Scottish referendum was provided through the Edinburgh Agreement of October 2012. Whether the same consent would be forthcoming in future, and whether the Scottish government would henceforth require that consent, is a complicated question that cannot be addressed here.

20 The Treasury would be mindful of the recent fiasco involving construction of aircraft-less aircraft carriers that were too costly to cancel due to penalty clauses built into contracts. See ‘Carrier Strike: The 2012 Reversion Decision’, House of Commons Committee of Public Accounts, HC 113, 3 September 2013,

21 During the Scottish referendum debate, there was no agreement on how to refer to the state that would succeed the UK if Scotland departed from the Union. ‘rUK’ was the most common acronym, standing for ‘rest of the UK’.

22 See Malcolm Chalmers and William Walker, ‘Will Scotland Sink the United Kingdom’s Nuclear Deterrent?’, Washington Quarterly, vol. 36, no. 3, July 2013, pp. 107–22.

23 Barry Staw, ‘The Escalation of Commitment’, in Z. Shapira (ed.), Organizational Decision Making (Cambridge: Cambridge University Press, 1997). On the linked issue of technological entrapment or lock-in, see William Walker, ‘Entrapment in Large Technology Systems: Institutional Commitment and Power Relations’, Research Policy, vol. 29, no. 7, 2000, pp. 833–46.

24 ‘Faslane Contracts Reignite Row Over Trident Renewal’, BBC News, 31 August 2015,

25 A poll, sponsored by Lord Ashcroft, contradicting usual findings about Scottish public attitudes towards Trident, was reported in George Eaton, ‘Is the Scottish Public Really Opposed to Nuclear Weapons?’, New Statesman, 10 May 2013,

26 Sir Simon Jenkins, distinguished journalist and chair of the National Trust from 2008–14, has been one of Trident’s most outspoken critics. See, for instance, ‘The Case for Trident is Absurd. Scotland May Help Us to Get Rid of It’, Guardian, 15 August 2014,

27 The Labour Party’s defeats in the 1983 and 1987 general elections were partly attributed to its advocacy of unilateral nuclear disarmament.

28 Hugh Chalmers and Malcolm Chalmers, ‘Relocation, Relocation, Relocation: Could the UK’s Nuclear Force Be Moved after Scottish Independence?’, RUSI Occasional Paper, London, August 2014,

29 For the memorandum on life extension that Garwin submitted to the Defence Select Committee, with Philip Coyle, Ted Postol and Frank von Hippel’s approval, see ‘Memorandum From Professor Richard L Garwin’, Written Evidence, House of Commons Select Committee on Defence, 10 January 2007,

30 Might an American offer to allow the British nuclear force to use King’s Bay in Georgia, perhaps temporarily while an alternative base in England or Wales was being developed, give the UK government confidence that it could press ahead with manufacture without risking loss of its investment if Scotland became a sovereign state? If such an intergovernmental understanding were reached, should it be made public at the time of the Main Gate decision?

31 ‘Scotland Could Go Nuclear over the Retention of Trident’, Financial Times, 9 March 2007,

William Walker is Emeritus Professor of International Relations at the University of St Andrews

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Survival: Global Politics and Strategy

October-November 2015

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