Bridge to Nowhere: UK security strategy in the ruins of Atlantis

As Western security alliances fragment, Richard Reeve charts the implications for the UK’s most fundamental strategic assumptions, and makes the case for ‘thinking beyond the unthinkable’ in the government’s next National Security Strategy.

While Ukraine has acutely felt its vulnerability since 2014, only in the last month has the precarity of Europe’s position become startlingly clear. Having already laid claim to Canada, Greenland and Gaza, this past month US leaders Trump and Vance have attacked and undermined European democracies, dubbed Volodymyr Zelenskyy a ‘dictator’, and grasped at his country’s mineral wealth while unilaterally seeking to end the Russia-Ukraine war on Moscow’s terms. With Trump burying America’s closest alliances beneath his clear contempt for multilateralism, international law, and liberalism in all its forms, by 23 February Germany’s incoming Chancellor Friedrich Merz was pledging “to strengthen Europe as quickly as possible so that, step by step, we can really achieve independence from the USA”.

More than any other European state, the UK is enmeshed in security alliances with the United States that conflict with the security challenges and interests of its own continent. Caught between his US and European allies, Keir Starmer has scrambled to summits in Paris, Washington and London to try and heal the trans-Atlantic rift. Balancing between Europe and the United States – which requires straddling painful divides within British politics – may soon no longer be possible or desirable.

With this quandary in play, Starmer’s team is racing to complete a new National Security Strategy by June. The last such document, the Integrated Review Refresh of 2023 (IRR23), laid four big bets on the future. Trump’s at best transactional, at worst adversarial, relationship with traditional European allies has made all these bets look like costly mistakes.

Bet 1 – The US security guarantee

The first, biggest bet was that the UK could depend on the US as its closest ally and security patron within a functional North Atlantic Treaty Organisation (NATO). This has been the central, and usually unspoken, assumption that has underpinned all UK defence policies since the 1940s, as well as the North Atlantic Treaty more broadly. Yet US leaders have served notice that this cannot be taken for granted, and NATO may even be weaker with an ambiguous or hostile United States within it.

Whereas most of Europe is formally allied with the United States through the 76-year-old nuclear-armed NATO and buys much of its equipment from it, the UK has much more complex ties, especially in intelligence-sharing, base-sharing, nuclear weapons development and wider industrial collaboration. This includes a permanent seat on the UN Security Council, the vastly complex Five-Eyes intelligence network, that incorporates the other three ‘Anglosphere’ states: Australia, Canada and New Zealand, as well as overt and covert US use of UK military bases and spying facilities on Ascension Island, Cyprus, Diego Garcia, Gibraltar, within the UK, and under the surrounding seas. The UK is also industrially embedded with the United States through, for example, BAE Systems. A UK-registered company, BAE is the monopoly supplier of submarines, fighter aircraft and much other equipment to the UK military but actually sells twice as much into the US market, where it also has vast industrial operations.

This gives the UK a degree of leverage over the US, despite its greater dependency on it. Washington has more to lose from unravelling its alliance with the UK than with any other European country. If the wider NATO alliance does fold, the US would likely still want a separate relationship with the UK – potentially presenting the UK with some hard choices.T

Bet 2 – Nuclear cooperation

The second, and most costly, bet of the IRR23 is on nuclear reactor technology, and that the UK has the economic and technological capacity to renew its submarine-based nuclear weapons system. Here again, the UK is in significant trouble, as the government’s Infrastructure and Projects Authority has rated the ‘Core Production Capability’ (Rolls Royce’s PWR3 nuclear reactor for the in-construction Dreadnought class of ballistic missile-carrying submarines) as ‘unachievable’ for two years running. Reportedly based on US-transferred technology, it is unclear what influence the US government has over the troubled PWR3 project.

In response, in January the government awarded Rolls Royce a £9 billion contract to expand its production facilities. Over the next decade, the nuclear programme is forecast to account for nearly 39% of all planned capital expenditure by the MoD, and somewhere between one-quarter and one-third of UK defence spending overall. Colossally subsidised, Labour and Conservatives alike have been clear that this £117.8 billion (and rising) industry is too big to fail. Yet fail it will if the US rethinks its own subsidies and stops transferring technology and components on which the programme depends –including Trident missilesand their ‘Common Missile Compartment’. Already the Trump administration has complained that the UK “got an unfairly cheap deal with Trident”.

Under the most optimistic assessments, the first of the new Dreadnought submarines will not enter service until the early 2030s. Thus ‘continuous at sea deterrence’ (CASD) patrols now seem likely to be at least paused after six decades. By then, three of the four current Vanguard class submarines will be beyond 35-years-old, and presumably retired. With no other means of deploying nuclear weapons, the UK will then effectively cease to be nuclear-capable, even if US-owned Trident missiles remain available. This de facto nuclear disarmament compounds snowballing questions of sovereignty, industrial capacity, opportunity cost, technological change, legality and ethics to advocate against the UK continuing to sacrifice other priorities in pursuit of such weapons of mass destruction.

Bet 3 – Technology superpower

The third big IRR23 bet was on the UK’s ability to develop itself as a “Science and Technology Superpower”. Although this is understandable amid global technological change, it appears not to support socially useful scientific sectors, and is a long shot given the UK’s limited commercial heft relative to US and East Asian competitors. Under Trump and Vance, backed by Elon Musk and other US tech ‘broligarchs’, the US has put artificial intelligence (AI) and other big tech at the heart of its own strategy for dominance – investing big and continuing the Biden administration’s efforts to deny China access to critical US technology and components.

Inevitably, the tech sector appears to be central to Washington’s talk of a new US-UK trade deal. This won’t be the kind of free trade deal of which Brexit advocates once dreamed. Starmer today must aspire merely to avoid the kind of crippling tariffs imposed on NATO allies in Canada and the EU. As the UK’s largest export market (21%) after the EU (41%), the US has leverage and it should be concerning that market access and regulatory alignment of the tech sector is reportedly key to US-UK trade talks.

Starmer has already shown remarkable acquiescence to the libertarian US position on tech development and regulation. On 11 February he joined Vance in refusing to endorse the outcomes of Macron’s Summit for Action on AI in Paris, citing unelaborated concerns about the impact of global regulation on UK growth and national security. In Washington last week, Starmer also made time to visit the office of controversial US ‘defence analytics’ firm Palantir. Courting investment from tech and security firms is also at the core of ongoing UK efforts to deepen trade partnerships with Israel, set out in the 2030 Bilateral Roadmap of March 2023.

It thus seems that the UK’s strategic priority of developing greater sovereign autonomy over key technologies is being sacrificed to pursue science and tech growth at all costs – i.e. as a dependent sub-contractor to some very compromised partners. That may be good for growth, but likely undermines the UK’s ability to set and pursue its own interests or wider international cooperation.

Bet 4 – AUKUS

Finally, the big new bet that Johnson and Sunak made from 2021, as Johnson’s ‘Global Britain’ sought to assert itself in the economically ascendant ‘Indo-Pacific’, was that the UK could design, and build the reactors for, at least five new nuclear-powered submarines for Australia under the Australia-UK-US (AUKUS) partnership, as well as deploy one of the Royal Navy’s six patrol submarines to Perth from 2027. Yet Russia’s invasion of Ukraine five months after AUKUS’s launch, and Sunak and Starmer’s less confrontational approach to China, have made UK military assertiveness in Asia much less desirable, and no more credible.

By showing British military support for US geostrategic objectives in Asia, the AUKUS partnership may bolster the UK-US alliance, and subsidise the design and build challenges of the PWR3 nuclear reactor project. AUKUS’ ‘Pillar 2’ covers trilateral cooperation on research and development of new military technologies, including cyber, AI, quantum technologies and hypersonic missiles, furthering the UK’s quest for tech superpowers. In reality, AUKUS locks the UK into serving and depending on the United States and its distinct interests, and into accepting steep strategic and economic costs – which will only grow if US policy and objectives in Asia become more erratic.

Enter the Trump administration. It remains unclear whether it aims to double down on ‘great power competition’ with China, and thus prepare for war in the Pacific, or aspires to strike a grand bargain with Beijing that might allow it to disengage from the region and its allies there. Defense Secretary Pete Hegseth has claimed Trump is “very aware, supportive of AUKUS”; Trump himself asked publicly what AUKUS is during his meeting with Starmer. The President may yet balk at or discard Biden’s pledge to transfer three of the US Navy’s behind-schedule Virginia-class submarines to Australia, while rewarding the UK’s troubled industrial base. Trump’s pick for the Pentagon’s head of defence policy, Elbridge Colby, has made plain his own opposition to the AUKUS submarine programme. Since the US owns much of the technology, any change of policy in Washington would leave both Australia and the UK high, dry and out-of-pocket.

Strategic advantage for whom?

While the UK’s national security challenges and interests are fundamentally rooted in Europe, its national security policy is far more deeply interwoven with that of the US. Its cross-party consensus for three generations has been to support American rules and domination, a proxy strategy that IRR23 calls ‘securing strategic advantage’. If the US is abandoning both Ukraine and its security guarantees for European NATO states, where does it leave the UK? Starmer’s recent diplomacy aims to make the UK the bridge between the US and Europe, but Brexit has made this work harder by undermining the UK’s foundations in Europe.

For British intelligence, defence, political and industrial elites, envisaging a decoupling from US interests, and the potential costs, has long been unthinkable. With the US now shredding the rules, abandoning allies and courting not just autocrats but the UK’s prime adversary, does the UK have the impetus and integrity to chart its own path?

It is unlikely to happen without a firm shove from Washington. Events are moving fast, but Trump is currently smiling in Britain’s direction, and US security elites probably do value UK bases and intelligence assets. The UK government will surely do all it can to cling to the alliance, and do its utmost to remain (in its limited way) a nuclear power.

Will the US stick with the UK as it untethers from Europe? Perhaps, but Trump and Vance clearly won’t brook public dissent from allies, and an uncritical alliance may be morally (and this should long have been the case well before Trump), practically (given the sharp divergence of threat perceptions) and politically (Trump is massively unpopular with UK voters) unsustainable. The United States is equally enmeshed with Canada, which Trump has sought to humiliate, even mooting revising their border and its ejection from Five Eyes and the North American Aerospace Defense Command (NORAD), which the US relies on to monitor Canadian airspace. What if Trump decides the United States needs Bermuda or a sub-Antarctic foothold in the Falklands? What if he covets the waterfront property potential of the Chagos islands?

Given the UK and Europe’s shared fears, and the doubts over NATO’s future viability, for the first time since the Brexit referendum the factors pulling the UK towards Europe are ascendant. However, the rise of nationalist, pro-Russian parties in France, Germany and elsewhere could easily shatter the foundations of European security cooperation. And if relations between Washington and Brussels deteriorate, as Germany, Denmark and others seem to foresee, the UK may be forced to pick sides.

Thinking beyond the unthinkable

With a national security strategy review being drafted, Westminster has but a few weeks to fundamentally change its thinking to remove the central assumption that the United States is a reliable ally, or even an enduring friend, and to be open, not least to itself, about what the trade-offs of even a qualified friendship will be. From NATO security guarantees, AUKUS’ viability and the credibility of a semi-sovereign nuclear deterrent, to tech ambitions and the Indo-Pacific tilt, all of the Integrated Reviews’ big bets are off.

Starmer’s diplomatic activism aims to buy time for Ukraine and Europe – but it also illustrates inertia and a deep reluctance to upset eight decades of dependency. Hope is fast fading that MAGA is an aberration, and that acts of tribute can enable Britain to sidestep the retribution directed elsewhere.

Difficult as it is, to avoid unthinkable consequences tomorrow we need to think through and beyond ideas that have been anathema to policy-makers for generations. This means: correcting course from ever-greater dependence on an erratic and autocratic United States; opposing the drive towards neo-imperialism from Washington and Moscow alike; maintaining shared and mutually beneficial security in partnership with more like-minded states and societies; refusing to gamble with the world’s climate, development and tech regulation to appease the ascendant anti-liberal oligarchy; and patiently revitalising a fair and representative international legal order that reflects what the vast majority of the world’s states and peoples want and need.

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The views and opinions expressed in posts on the Rethinking Security blog are those of the authors and do not necessarily reflect the position of the network and its broader membership.

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Image Credit: No 10 Downing Street, via Flickr. Prime Minister Keir Starmer reads his notes as he prepares to host a European Leaders Summit at Lancaster House, London, 02 March 2025. Picture by Simon Dawson.

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The article was amended on 07 March 2025 to include reference to Trump’s reported threats to NORAD.