Paul Ingram and Ian Davis*
11 April 2025
President Trump is highlighting the expanding transatlantic gulf in values and attitudes. Former British Ambassadors to Washington believe this is likely permanent. This realisation has prompted concerns that the US could withdraw support for the UK Trident nuclear weapon system, and claims from the government and its allies that Trident is operationally independent of the United States. These claims are false, as outlined effectively in a recent article from Becky Alexis-Martin of Bradford.
Operational dependency: the facts
True, the UK can fire nuclear weapons without the permission of the United States. But this is not the point.
Operational dependency is built in. Britain’s nuclear weapons are devoted to NATO’s integrated nuclear posture. Patrols are coordinated with the United States. Some of the targeting capability is dependent upon US GPS (though the missiles can operate without it at lower accuracy).
The UK submarines regularly visit the US Naval base at Kings Bay, Georgia, to swap out Trident missiles from the common US-UK pool maintained by the Americans. And, it is said time and again that the United States does not have the power to control the missiles. These are hugely complex, sophisticated pieces of kit, and whilst there are modest facilities at Coulport in Scotland to store the missiles, they are not inspected in detail there. How confident can any of us be, including the Royal Navy, that they do not have some form of kill switch?
Many of the components of the submarines and the warheads are also of US origin. These need servicing and are sometimes replaced. The UK lobbied the US Congress five years ago to fast-track development of the new US W93 warhead. This was because the UK’s own new warhead programme contained W93 components and uses US-made Mk7 reentry vehicles.
The PWR3 reactor that will power the Dreadnought submarines is far more reliant on US designs and components than its predecessor the PWR2, which was seen as having reached an embarrassing technical deadend. The Common Missile Compartment (the guts of both the new US Columbia class ballistic missile submarines and the UK Dreadnoughts) contain twelve missile tubes, command and control systems and crew quarters. All designed, developed and manufactured in the USA.
Even with this extensive support, the project is shaky. The Dreadnought nuclear reactor programme was given a red rating over the last three years by the UK Infrastructure and Projects Authority (IPA). This means the “successful delivery” of the £3.7 billion project “appears to be unachievable”. Perhaps more seriously still, developments in anti-submarine warfare may make the submarines more open to attack. Quantum observation and detection technology, for example, is one of several technologies that could expose submarines and render them vulnerable to attack, something we reported on back in 2016.
So, both the renewal of the system and its maintenance is heavily dependent upon the United States and heavily vulnerable to further delay and redundancy. The independent Trident Commission concluded in 2014 that, “If the United States were to withdraw their cooperation completely, the UK nuclear capability would probably have a life expectancy measured in months rather than years”. Decisions taken to deepen dependency on Washington in gathering together elements of Trident renewal have exacerbated this.
Vulnerable to the Art of the Deal
As UK negotiators desperately attempt to agree an urgent trade deal with Washington this week, can we be sure that Donald Trump will not seek to withhold his ‘beautiful Trident missiles’ from the UK in exchange for US access to the NHS, further penetration by US tech firms, or the removal of obstacles to imports of American chickens and other agricultural produce into the UK market? In the choice between keeping its nuclear weapons or protecting British farmers and consumers, which way will this government land? Could the UK’s Trident dependency already help to explain why the Prime Minister has been so coy about confronting Trump’s tariffs?
Because Trump’s actions have exposed this vulnerability, Malcolm Rifkind, former Foreign and Defence Secretary, and co-chair of the Trident Commission, recently proposed that the UK explore greater cooperation with Europe in developing and deploying nuclear weapons. However, a Chatham House analysis shows how challenging this would be, though we believe it underestimates the technical and political obstacles.
The UK is obviously exposed and dependent on the US in all sorts of ways, but our biggest vulnerability is in placing such high regard to the so-called nuclear crown jewels. Rather than being the ultimate guarantor of our survival and independence, a line that successive governments and nuclear experts have spun for over 70 years, they may well turn out to be Britain’s Achilles heel.
We have argued elsewhere that Britain could still turn this situation around by cancelling Trident replacement as part of revived nuclear disarmament negotiations between Europe and Russia. This would not only release at least £3 billion per annum to benefit other UK government spending, security or otherwise, but also be a key step in decoupling the UK from the clutches of Washington. All that is needed is the political will.
*Disclosure statement: between the two of us we ran the British American Security Information Council (BASIC) between 2000 and 2019, one of the UK’s leading think tanks focused on nuclear weapons policy from a critical perspective. We ran the Trident Commission (2011-14), which was co-chaired by Malcolm Rifkind, Des Browne and Menzies Campbell and composed of senior parliamentarians, as well as top military and diplomatic people. It was briefed by senior officials at the Ministry of Defence and leading experts, and examined questions associated with Britain’s nuclear arsenal and its renewal.