November 8th 1983 is now recognised as one of the most dangerous moments in history, when Soviet fingers hovered prerilously over the nuclear button.
On this near fateful day, senior figures in the Soviet Union convinced themselves they were about to come under nuclear attack from the West. 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 - the destruction of the world - beckoned. The intelligence communities in the US, Europe and the former USSR have never before admitted to the scale of the crisis.
This programme tells the dramatic story behind this sequence of events.