The letters of last resort are four identically worded handwritten letters from the

prime minister of the United Kingdom The prime minister of the United Kingdom is the head of government of the United Kingdom. The prime minister Advice (constitutional law), advises the Monarchy of the United Kingdom, sovereign on the exercise of much of the Royal prerogative ...

to the commanding officers of the four British ballistic missile submarines and stored on board of each. They contain orders on what action to take if an enemy nuclear strike has both destroyed the

British government His Majesty's Government, abbreviated to HM Government or otherwise UK Government, is the central government, central executive authority of the United Kingdom of Great Britain and Northern Ireland.

and has also killed or otherwise incapacitated both the prime minister and their designated "second person" of responsibility, typically a high-ranking member of the Cabinet such as the

deputy prime minister A deputy prime minister or vice prime minister is, in some countries, a Minister (government), government minister who can take the position of acting prime minister when the prime minister is temporarily absent. The position is often likened to th ...

or the

first secretary of state First Secretary of State is an office that is sometimes held by a minister of the Crown Minister of the Crown is a formal constitutional term used in Commonwealth realms to describe a minister of the reigning sovereign or viceroy. The term ...

. If the orders are carried out, the action taken could be the last official act of

His Majesty's Government His Majesty's Government, abbreviated to HM Government or otherwise UK Government, is the central government, central executive authority of the United Kingdom of Great Britain and Northern Ireland.

. If the letters are not used during the term of the prime minister who wrote them, they are destroyed unopened after that person leaves office, so that their content remains unknown to anyone except the issuer.

Process

A new prime minister writes a set of letters immediately after taking office and being told by the Chief of the Defence Staff "precisely what damage a Trident missile could cause". The documents are then delivered to the submarines in sealed envelopes, and the previous prime minister's letters are destroyed without being opened. In the event of the deaths of both the prime minister and the designated alternative decision-maker as a result of a nuclear strike, the commander(s) of any nuclear submarine(s) on patrol at the time would use a series of checks to ascertain whether the letters of last resort must be opened. According to

Peter Hennessy Peter John Hennessy, Baron Hennessy of Nympsfield, (born 28 March 1947) is an English historian and academic specialising in the history of government. Since 1992, he has been Attlee Professor of Contemporary British History at Queen Mary Univ ...

's book ''The Secret State: Whitehall and the Cold War'', the process by which a commander would determine if the British government continues to function includes, amongst other checks, establishing whether

BBC Radio 4 BBC Radio 4 is a British national radio station owned and operated by the BBC. The station replaced the BBC Home Service on 30 September 1967 and broadcasts a wide variety of spoken-word programmes from the BBC's headquarters at Broadcasti ...

continues broadcasting. In 1983, the procedure for

Polaris Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...

submarines was to open the envelopes if there was an evident nuclear attack, or if all UK naval broadcasts had ceased for four hours.

Options

While the contents of these letters are secret, according to the December 2008 BBC Radio 4 documentary ''The Human Button'', there were four known options given to the prime minister to include in the letters. The prime minister might instruct the submarine commander to: # retaliate with

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear exp ...

s; # not retaliate; # use their own judgement; or, # place the submarine under an allied country's command, if possible. The documentary mentions

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. ''

The Guardian ''The Guardian'' is a British daily newspaper. It was founded in Manchester in 1821 as ''The Manchester Guardian'' and changed its name in 1959, followed by a move to London. Along with its sister paper, ''The Guardian Weekly'', ''The Guardi ...

'' reported in 2016 that the options are said to include: "Put yourself under the command of the United States, if it is still there", "Go to Australia", "Retaliate", or "Use your own judgement". The actual option chosen remains known only to the writer of the letter.

Fiction

David Greig's 2012 play ''The Letter of Last Resort'' deals with the consequences and paradoxes of the letters. The play was first staged in February 2012 as a part of a cycle of plays on "The Bomb" at the

Tricycle Theatre The Kiln Theatre (formerly the Tricycle Theatre) is a theatre located in Kilburn, in the London Borough of Brent, England. Since 1980, the theatre has presented a wide range of plays reflecting the cultural diversity of the area, as well as n ...

in London, directed by Nicolas Kent, with Belinda Lang playing the role of the incoming prime minister and Simon Chandler, her advisor. The production was also seen at the

Traverse Theatre The Traverse Theatre is a theatre in Edinburgh, Scotland. It was founded as The Traverse Theatre Club in 1962 by John Calder, John Malcolm, Jim Haynes, Richard Demarco, Terry Lane, Andrew Muir, John Martin and Sheila Colvin. The Traverse Th ...

in Edinburgh, for the

Edinburgh Fringe The Edinburgh Festival Fringe (also referred to as the Edinburgh Fringe, the Fringe or the Edinburgh Fringe Festival) is the world's largest performance arts festival, which in 2024 spanned 25 days, sold more than 2.6 million tickets and featur ...

later the same year. The following year it was broadcast on

, with the same cast, first transmitted on 1 June 2013. The KGB's attempts to obtain the contents of the letters of last resort are part of the plot of the BBC

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

spy drama '' The Game'' (2014).

Footnotes

References

External links