During the Cuban missile crisis the world held its breath, convinced that it was on the brink of all-out nuclear war. The critical moment was said to be 'Black Saturday', October 27, when Robert McNamara, the US Defence Secretary, recalled going out on to the White House lawn to take what he thought would be his last sight of the grass and open air.

The relief was extraordinary the next day when the Soviet Union appeared to back down and announced that it would withdraw its nuclear missiles from Cuba. The United States proceeded to turn the crisis into a diplomatic and political triumph by astute marketing that depended on the creation of a myth, embodied in the phrase from Dean Rusk, the Secretary of State, that 'we were eyeball to eyeball -- and the other guy just blinked'.

That mythology of the crisis, along with accounts of the cool resolve of President John F. Kennedy in answering Nikita Khrushchev's emollient first letter rather than the tougher second one, has proved surprisingly durable. Subsequent revelations suggest that the mythology was at best incomplete. It is now clear that although the US Navy's monitoring procedures were neither efficient nor fast enough to notice and report the fact, the Soviet ships carrying missiles and warheads to Cuba were turned back early on in the crisis. The White House was informed of the retreat on October 24, three days before the famous 'Black Saturday'. It was in response to this news that Rusk made his famous 'eyeball-to-eyeball' remark.

While the US increased the state of its military alert to Defcon 3 and to Defcon 2 for Strategic Air Command, with nuclear bombers in the air and others on 15-minute alert, the Soviets did not follow suit. There was no countervailing pressure in Europe and US Air Force General David Burchinal, deputy chief of staff, later recalled: 'The Russians did not increase their alert; they did not increase any flights, or their air defence posture. They didn't do a thing, they froze in place. We were never further from nuclear war than at the time of Cuba, never further.'

Moreover, while the mythology suggested that JFK had secured his triumph only by promising that there was to be no US invasion of Cuba, the deal that was reached also included a secret pledge to withdraw the US Jupiter missiles from Italy and Turkey 'within months'. This deal was presented to Soviet Ambassador Anatoly Dobrynin by Robert Kennedy, the president's brother, on October 26. In fact, in a meeting with UN Ambassador Adlai Stevenson on October 20, JFK had said that he was prepared to do this, but not immediately. In this sense, the makings of the diplomatic deal were in place before Black Saturday.

The dangers were real enough. Earlier in the year JFK had turned down a Khrushchev proposal for a hotline, which meant communications were slow. The shooting down of one U2 spy plane over Cuba and the straying of another into Siberian airspace -- both on October 27 -- could have triggered war. The decision of a Soviet submarine, Captain Vassily Arkhipov, not to use his nuclear-tipped torpedoes when being attacked by small target-finding depth-charges may have prevented war.

Had the US invaded Cuba, as the Joint Chiefs of Staff urged, the Soviets had 45,000 troops, missiles and a hundred tactical nuclear warheads, Hiroshima-size, with which to retaliate. Guantanamo, the US naval task force and perhaps Miami would have been incinerated, since the Soviet commander in Cuba was authorized to use them.

The real question is how far the myth shaped the thinking of JFK's successors into a conviction that firm resolve and nuclear alerts succeeded, and appeasement would always be seen as failure.

Martin Walker is author of The Cold War: A History

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