World on the nuclear brink

Soviet intermediate and tactical missiles were welcomed by Fidel Castro as defence against further attack from the United States after the failure of the Bay of Pigs invasion.

These could be fired at the US, just as equivalent missiles in Turkey and Italy could reach the Soviet Union.

Kennedy saw this logic when he acquiesced in the withdrawal of all Jupiter missiles from Turkey and Italy, as well as agreeing not to invade Cuba. In return, Nikita Kruschev removed his nuclear weapons.

Cold logic did not always rule. There was political pressure on Kennedy not to give an inch and some of the US chiefs of staff called for a preventive war against the Soviet Union.

The main danger stemmed from the commitment of both sides to pre-emptive strikes in some circumstances.

A flashpoint could be reached if a lower commander exceeded or misjudged his authority, as when a surface-to-air missile shot down a US U2 reconnaissance plane over Cuba.

When another U2 entered Soviet air space off course, the Soviet strategic forces were placed on high alert for the first time in their history, in the knowledge that nuclear weapons had to be used before the other side could use them against you.

A deadly serious incident during the US naval blockade of Cuba was disclosed 40 years later. Depth charges were used to force a Soviet nuclear submarine to surface.

As they were running out of air, the captain ordered the assembly of the nuclear torpedo to battle readiness, screaming: "Maybe the war has already started up there. We will die, but we will sink them all."

Caution prevailed, but Len Scott asks: "Was this the moment when the world really did stand on the brink of nuclear war?"

A chronological account of the crisis would have been more coherent than Scott's thematic structure. But his assessment of "the most dangerous days in human history" is chilling testimony to the high risk of future nuclear catastrophe.

JOHN MOORE