The deadliest decision Keir Starmer will have to make today

Within hours of taking up his new post, there’s one job Sir Keir Starmer will have to do today, which will literally be a matter of life or death. 

Tony Blair reportedly ‘turned white’ when he was told to complete the order, while John Major said it was ‘one of the most difficult things I’ve ever had to do.’

This momentous task bestowed upon any new Prime Minister is to write four identical letters of instruction.

Known as the Letters of Last Resort, each detail what the UK should do in the face of nuclear attack if all those in authority have died.

It’s something that has been done since 1969 when the UK started using submarines for their deterrent, and the contents of the letters have always been kept top secret. 

‘When a new Prime Minister walks into office one of the very first things that happens is that they get briefed on the Trident nuclear weapon programme and the mechanisms for their release,’ explains Paul Ingram, Research Affiliate at the University of Cambridge Centre for the Study of Existential Risk. ‘The letter are a command to the submarines if London has been hit and leadership has been decapitated above ground.’

Once penned, the instructions are put into a safe within a safe, alongside anotherletter of  instructions on the final steps that need to be taken before opening the Letter of Last Resort from the PM. Then they are delivered to  the commanding officers of the Vangaurd, a fleet of four submarines that carry nuclear deterrents.

Once a PM steps down their letters are burnt without ever being opened, so no one will ever know what they chose to do. 

What are the choices? 

While no one knows for sure, according to a Radio 4 documentary The Human Button, there are said to be four options given by the PM: do nothing, find an ally (suggestions are though to be America or Australia), use their own judgement, or – the most deadly decision of all – retaliate with nuclear weapons.

‘With the PM presumed dead, the commander may well opt to use their own judgement given they are alive and able to use brain cells,’ adds Paul. ‘Yes, these are are trained military people, trained to follow orders but they are also human beings.’

It’s little wonder that writing these letters weigh heavy on the shoulders of those in power. 

The Royal Navy’s Vanguard Class consists of the four nuclear-powered ballistic missile submarines – HMS Vanguard, Vengeance, Victorious and Vigilant – which carry a deadly amount of weaponry.

‘Each submarine has 12 operational tubes which can deploy between 8-12 missiles and, it’s believed, around 50 warheads, explains Paul.

‘That’s seven or eight times as destructive as the bomb which flattened Hiroshima in 1945, killing over 140,000 civilians.’

Tom Unterrainer, Chair of the Campaign for Nuclear Disarmement, tells Metro: ‘Within hours of a Prime Minister entering power they are indoctrinated into a nuclear framework. In their briefing they are taken through a number of scenarios by senior military – which cities do they hit, how many will die, what are the possible repercussions.

‘Writing the letter is one of the first acts of an incoming PM, but at no point during the election campaign has anyone really asked the question of what Keir Starmer thinks about unleashing mass death genocidal nuclear war the world… It’s a weird one.’

How will they know when to open them

The letters are only to be opened if a nuclear attack has killed or otherwise incapacitated both the Prime Minister and their designated “second person” – usually a high-ranking member of the Cabinet such as the deputy prime minister or the first secretary of state – and if all contact with Naval command has been lost. 

One of the indications that British Government may have been destroyed is, randomly, said to include the BBC Radio 4 Today programme. According to Lord Peter Hennessy, a history professor and Member of The House of Lords, if it isn’t heard for three consecutive days it’s a sign that something is very seriously wrong. 

However, there are of course other triggers, explains Paul.

‘When on patrol these submarines have very limited communications with mainland and it only goes one way. If they were to reach out from the depths of the ocean it could potentially give their location away. They essentially have to sit and wait.

‘So if those signals from the Admiralty were to stop for a prolonged period, that would be one trigger. They would also listen out for broadcasts such as the World Service – and maybe Radio 4 – and if they were absent, the submarine would then come up to the shallows to see if they could get signal.

‘Again, this could cause them to be a target, so it is a decision that couldn’t be taken lightly. However, if the world appeared dark above ground, that would be another sign something has happened.’

Opening the letters

In the event of a doomsday scenario, the Vanguard commander will open the safes containing the letter and carry out the instructions contained within.

‘The assumption is that the person who has written them is already a corpse, so the question really is do they follow the instructions of a dead person or not – especially when it could contribute to the destruction of all life,’ says Tom.

‘I’ve worked with Commander Robert Forsyth, who was on the Polaris nuclear submarine, and he did something called the perisher course. This trains those on the subs the drill to fire weapons and the choices they have to make. They get a legal briefing and reassurances, but in reality there are still big question marks surrounding the laws of war.’

‘If the commander decides to retaliate, they would then consult with two other officers on board,’ adds Paul. ‘If all three agree they would plot their targets and programme their missiles. Then they would use a dual key system and a trigger to fire the weapons.’

To give an idea of the extent of damage, Tom says, ‘If a fully loaded, powered up weapon was launched and hit somewhere London, it would all be gone. There would be firestorms, millions dead in an instant.’

James Callaghan, who was Prime Minister from 1976-1979, is the only former leader to reveal what he would have done.

‘If we had got to that point where it was, I felt, necessary to do it – then I would have done it,’ he told a BBC documentary in 1988.

‘I’ve had terrible doubts of course about this. And I say to you that if I had lived after having pressed that button, I would never, never have forgiven myself.’

Meanwhile, despite spending a lifetime trying to ban nuclear weapons, when Jeremy Corbyn was standing for election in 2019, he said that if elected PM he would write the letters.

‘I will write the appropriate letters to our commanders,’ he said, adding that ‘any nuclear weapon used anywhere in the world is a disaster.’

But what about our new Prime Minister?

‘Keir Starmer has said he’s been prepared to use nuclear weapons – all the party leaders have,’ says Tom. ‘Which is essentially saying you’re willing to push a button that can unleash genocidal nuclear war on planet earth. That’s the level we’re operating on.’

For Paul, if he was asked to write the Letters, his instructions would be to ‘either do nothing or find an ally,’ he says.

‘The point of the Vangaurd missiles is to act as a deterrent, for other countries to know that even if you destroyed government above ground, there is the risk of an attack from the ocean.

‘For me, those missiles aren’t for retribution, they are to deter action. So sending warheads off after London had been destroyed would be a war crime and a gratuitous murder of millions of civilians.’

However, until Keir Starmer has written his Letters of Last Resort, former PM Rishi Sunak still retains a sliver of power, as-his secret instructions on board the submarines at sea will remain valid until they can be exchanged.

Do you have a story you’d like to share? Get in touch by emailing Claie.Wilson@metro.co.uk 

Share your views in the comments below.