An extremely powerful programme, this documentary focuses on 8 November 1983, a date now recognised as one of the most dangerous moments in the entire history of the Cold War.

On this near-fateful day, a series of accidents nearly unleashed the Third World War. Senior figures in the Soviet Union had convinced themselves that they were about to come under nuclear attack from the West, and the vast Soviet nuclear arsenal of missiles, bombers and submarines were put on maximum alert, ready to launch a full nuclear retaliatory attack on Western Europe and the US. Armageddon beckoned.

This documentary tells the dramatic story behind this sequence of events when Soviet fingers hovered perilously over the nuclear button. The intelligence communities in the US, Europe and the former USSR have never before admitted to the scale of this crisis.

1983 was a time of heightened tension in the Cold War. President Reagan began a huge military build-up, spending a trillion dollars a year on defence spending. In March of that year he openly called the Soviet Union an "evil empire" and a few weeks later he launched his Star Wars initiative. At the end of August, relations between East and West deteriorated even further when the Soviets shot down a civilian Korean airliner, flight KAL007, which had strayed over a sensitive military zone near the Kamchatka peninsula, with great loss of life.

To make matters worse, in November Nato began an exercise called Able Archer. This regular military war game rehearsed the process of how to launch nuclear weapons. For the Soviets, who always believed an attack from the West would come in the guise of a military exercise, this was the last straw. They convinced themselves this was not a military exercise but was the real thing. Fingers hovered over the nuclear button as the Soviets believed America was about to launch its missiles against them.

Among those interviewed in this documentary are Robert Gates, deputy head of the CIA in 1983 and now Secretary of Defense in the Bush administration; Vladimir Kryuchkov, head of the KGB; Oleg Gordievsky a senior KGB officer but a double agent also working for British intelligence; an East German spy with the code name Topaz who had penetrated the most senior levels of Nato; and senior US, Soviet and Nato military chiefs who were caught up in this remarkable drama that took the world to the brink of Apocalypse.

Highly recommended.