LAST week a UK nuclear weapon Vanguard-class submarine returned to its base in Faslane, covered in algae and barnacles, reportedly after a patrol that lasted more than six months.

This prompted the pro-navy (and pro-nuclear-weapon) magazine Navy Outlook to publish a long article discussing the increase in the length of patrols and suggesting that this is down to the difficulty, due to refits and maintenance problems arising from skill shortages, of maintaining the pattern of always having one boat on patrol at all times. The article acknowledges that there is now great pressure on the submariners and that risks are being taken to maintain the patrol pattern.

The four Vanguard-class boats are now more than 30 years old and the replacement Dreadnought- class is already well behind schedule, so the question arises as to whether the current submarines can be patched and crewed sufficiently to close the potential gap in availability.

The Dreadnought programme is seriously hampered by a shortage of assembly space at Barrow and delays to the Derby unit where the reactor cores will be built. The UK Government refuses to say when it expects the new boats to be ready. The stretching of the patrol length to six months and beyond suggests that the crisis point may not be far away and that in the interim more and more risks will be taken with material and personnel.

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The oncoming submarine crisis is not the only threat to the UK’s ability to maintain its nuclear weapon capability. The recent upsurge in the aspiration for Scottish independence should remind us that we are in a unique position with the potential not only to rid ourselves of these horrific weapons, but also to undermine the ability of the UK to persist with them since there is no credible alternative to the Clyde bases elsewhere the UK.

When the UK was setting up Polaris, its first system for the submarine launching of nuclear weapons, the Ministry of Defence conducted a study to determine what sites would be suitable for two essential items – a port for berthing the submarines and a nearby but separate armaments depot for storing the warheads and loading them onto the missiles in the submarines.

The study rejected all the projected locations in England and Wales (including Falmouth, Milford Haven, Portland, Devonport, Barrow, and completely new “greenfield” sites). So we have the submarines based at Faslane and the warhead storage and management facility at Coulport. The Clyde sites offer deep water access and a ready route to the Atlantic. Two other locations outwith the UK have been raised – one is moving the bases to King’s Bay in Georgia, US.

This would rip away the last tissue of pretence that the UK system is an independent one. Also mooted has been the sharing of the French facilities on Île Longue near Brest but this is seen as politically beyond the pale. In short, there is no feasible alternative to the Clyde bases. This analysis is accepted by the UK defence establishment. This makes Scottish independence a critical threat to the UK’s nuclear weapons.

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It has also been pointed out that the increasing fragility of the UK nuclear weapon system may have prompted the projected return of US nuclear weapons to the US base at Lakenheath in Suffolk. If the UK is seen as an increasingly wobbly part of the Nato nuclear fabric this may represent a belt-and-braces tactic.

The third shaky-nail factor is the growing worldwide movement for the complete elimination of nuclear weapons. The Treaty on the Prohibition of Nuclear Weapons (TPNW), which came into force as UN law in January 2021, has acquired huge worldwide support – to date 69 ratifications, 93 signatures and the regular support of around 130 states on the floor of the UN General Assembly, to say nothing of such strong supporters as Ireland, Austria, Pope Francis and The Elders. Meanwhile, financial institutions are disinvesting from nuclear weapons, frequently ascribing their stance to the TPNW.

The nuclear war threat is like an open petrol can that is kept close to an open fire on a shoogly table. This is a uniquely dangerous moment.

Yet there is an overwhelming desire for prohibition from the majority of UN member states, especially from those who would suffer the most from the climatic effects of an exchange of nuclear weapons.

We can hope that these three factors will enable a fundamental rethink of the UK’s nuclear posturing.

We can certainly hope that Scotland will take its own clear stance on the matter with worldwide support.

David Mackenzie is secretary of Secure Scotland