A massive Nato war games exercise took the world to the brink of nuclear disaster when the Soviet Union mistakenly believed the drill was a real attack, freshly released classified documents have revealed.
The threat came in 1983 when the British- and American-led exercise, Operation Able Archer, moved 40,000 troops across Western Europe.
Just how close Nato came to provoking the Soviet Union was only realised by the West when Oleg Gordievsky, a KGB double agent, briefed British officials in London.
The incident was detailed in British Cabinet papers obtained by the Nuclear Information Service through a Freedom of Information request.
The non-profit group, which campaigns against nuclear weapons, has claimed that the newly-disclosed brush with annihilation was a greater threat to the world than the Cuban missile crisis in 1962.
Nuclear Information Service director Peter Burt said: ‘We were one button-push from an irreversible nuclear war. This, in my view, was far more serious than the Cuban missile crisis.’