The papers, dated June 16, 1967, came just five years after the Cuban Missile Crisis pushed Cold War tension to the verge of World War 3. The US and the Soviet Union were bitterly locked in a nuclear arms race, battling for supremacy on the ground and in space, developing weapons of mass destruction to be used in the event that pressures blew the lid. Britain too was interested in protecting itself and Labour leader Harold Wilson oversaw the UK’s first submarine-based nuclear weapon system – POLARIS – a £250m plan to see off Chinese and Soviet threats by positioning four submarines East of Suez.
However, documents seen by Express.co.uk show Mr Wilson was also ready to make deals with the EEC, too – approaching de Gaulle for a meeting and discussing the possibility of working together in the future should Britain be accepted into the organisation.
The brief, dated June 16, 1967, reads: “Our first two POLARIS submarines have already been launched.
“We plan that all four should be operational by December 1969.
“We are taking steps to ensure that our POLARIS missiles will remain as effective weapons if the Russians complete their deployment of an ABM system.
“We have, however, decided not to buy the POSEIDON missile or to embark on the development of a new generation of nuclear weapons in co-operation with the United States.”
The UGM-73 POSEIDON missile was the second US Navy nuclear-armed submarine-launched ballistic missile (SLBM) system, powered by a two-stage solid-fuel rocket.
However, Mr Wilson was seemingly uninterested in this bit of kit and wanted to team up with the EEC instead.
His brief continued: “In a few year’s time, therefore, our military nuclear relationship with the United States, as it has existed since Nassau, will probably be coming to an end.
JUST IN: Falklands ship found: ‘Classified’ information recovered by Navy exposed in MoD letter
“We may then face a choice between renewing such nuclear cooperation with the United States or developing our nuclear policy in a primary European context.
“How this decision moves [forward] is bound to be determined largely by the possibilities presented to Britain of a fuller participation in Europe’s economic and political developments.”
The United Kingdom successfully joined the EEC on January 1, 1973, and would go on to develop Chevaline – a system to update and improve the POLARIS capabilities.
The Trident nuclear programme was launched in 1979 as an operational system of four Vanguard-class submarines armed with US Trident D5 missiles.
Today, the Trident nuclear programme is still active, and its purpose as stated by the Ministry of Defence is to “deter the most extreme threats to our national security and way of life, which cannot be done by other means”.
It is operated by the Royal Navy and based at Clyde Naval Base on the west coast of Scotland, 25 miles from Glasgow.
At least one submarine is always on patrol to provide a continuous at-sea capability.
Each one carries up to eight missiles and 40 warheads, although their capacity is much larger.