You would have thought that the Cuban missile crisis of 1962 had been picked over by historians, memoirists, political scientists, filmmakers, conference organizers and decision-making theorists, until there was absolutely nothing more to be said. But Michael Dobbs has ferreted in the files, and his riveting book "One Minute to Midnight: Kennedy, Khrushchev and Castro on the Brink of Nuclear War," does succeed in casting new light on aspects of the story hitherto carved in unassailable historical stone.

The Kennedy brothers did not abandon the hope of overthrowing Cuban leader Fidel Castro after the dismal failure of the attempted invasion at the Bay of Pigs the year before. Even as the missile crisis was beginning, Robert Kennedy (somewhat exceeding his responsibilities as attorney general) was still driving his people to come up with schemes for sabotage that could be blamed on the Cubans and provide the pretext for an invasion. Some — such as a proposal to hurl grenades at the Chinese Embassy in Havana — were approved by his brother, the president. Others — shooting down a civilian airliner, for example — apparently were not.

By the middle of 1962, the CIA had recruited a vast array of spies inside Cuba — and was overwhelmed by the mass of stuff it received. Its analysts were highly skeptical; they had read Graham Greene's satire "Our Man in Havana," about an amateur British spy fabricating intelligence for London. So they missed some remarkably accurate reports about the arrival of Soviet missiles, and on Sept. 19 they published a National Intelligence Estimate which flatly said, "The establishment on Cuban soil of Soviet nuclear striking forces which could be used against the U.S. would be incompatible with Soviet policy as we presently estimate it." The clinching aerial photos of the missiles arrived on Kennedy's desk less than three weeks later.

Among the myths that Dobbs dispels is the idea that U.S. and Soviet vessels came close to a clash but that the Russians blinked. For those of us who went to work that Wednesday morning wondering if we would ever see our families again, the worst seemed to be over when the missile-carrying Soviet ships turned back. In fact, Dobbs tells us, the U.S. warships were more than 600 kilometers away. Nikita Khrushchev, the Soviet leader, had already ordered his ships to turn back the previous day. The real crisis came three days later, on "Black Saturday," when both Kennedy and Khrushchev came very close to losing control of events. The U.S. military prepared to wipe out the Soviet military installations on Cuba. And in case the Soviets reacted, the U.S. Strategic Air Command was already geared up to wipe out the Soviet Union, as well.

Alfred A. Knopf One Minute to Midnight: Kennedy, Khrushchev and Castro on the Brink of Nuclear War By Michael Dobbs Alfred A. Knopf 448 pages. $28.95

The Soviet forces in Cuba — far more numerous than the Americans had realized — had already shot down a U2 spy plane belonging to the United States without authorization from Moscow. Now, under the command of Soviet Colonel Dmitry Yazov, an infantry regiment, armed (unknown to the Americans) with tactical nuclear weapons, prepared to take out the U.S. base at Guantanamo. Another U2 had accidentally strayed hundreds of kilometers into Soviet air space, and three bewildered Soviet submarines were forced to the surface by U.S. warships. One captain, who had lost contact with Moscow and did not know whether his country was at war or not, wondered whether he should use his nuclear torpedo to destroy the U.S. carrier task force. Neither side had fail-safe devices to prevent the unauthorized firing of a nuclear weapon by an individual commander or even an individual airman.

Moscow and Washington misinterpreted one another's messages throughout. It was as much by good luck as good judgment that Kennedy and Khrushchev stumbled into an arrangement whereby the Americans agreed not to invade Cuba, the Russians withdrew their missiles, and the Americans indicated — though not in public — that they would eventually withdraw a bunch of outdated missiles from Turkey.

Ironically, the man who gained most from the crisis was Castro. The Americans kept their word to Khrushchev and abandoned any further serious attempts to overthrow him. He continued to lead his country for decades after Kennedy and Khrushchev had passed from the scene. This, Khrushchev claimed, justified the reckless gamble he had taken by putting missiles in Cuba in the first place.

Khrushchev's colleagues did not agree, and a year later they removed him from office. But as one of them told a U.S. official, "You got away with it this time, but you will never get away with it again." From then on, the Soviet leadership was determined to achieve strategic parity. They succeeded, and bankrupted their country. Meanwhile, the world remained on the knife-edge of destruction.

Kennedy was, of course, the man of the moment. His cool decisiveness, his firm grasp of the politics both at home and in Moscow, had forced not only the Russians to blink, but the U.S. military as well. But this, Dobbs argues, was perhaps the most insidious myth of all. The idea took hold that the Americans had learned how to calibrate the approach to war, even to nuclear war, and that they could prevail not only by superior technology, but by superior logic — the logic of conflict and deterrent theory. But the truth, as Kennedy himself recognized, was that "there's always some son-of-a-bitch that doesn't get the word." The world was indeed lucky that none of the many things that went wrong proved to be decisive.

Kennedy and Khrushchev were trapped in an inescapable moral and political dilemma from which their successors were unable to escape for as long as the Cold War lasted. For deterrence to be credible, each side had to talk and act as if it were ready to launch a strategic exchange at a moment's notice: a nightmarish responsibility. But both Kennedy and Khrushchev knew what was at stake, and they were desperate to avoid an Armageddon. Even Margaret Thatcher, the formidably pugnacious British prime minister, once confessed that she was not sure she would be able to press the button "because I want grandchildren." The Cuban missile crisis was not the only time a combination of misjudgment and accident brought us close to nuclear catastrophe. The fortunate combination of Mikhail Gorbachev and Ronald Reagan — both morally repelled by the implications of nuclear deterrence — eventually returned us to a kind of normality.

The U.S. and Soviet militaries could not afford to indulge in such soul-searching, then or later. Their professional duty was to plan and win a nuclear war, and they comforted themselves with myths. During the missile crisis, the commander of the Strategic Air Command remarked that if a strategic exchange ended with two Americans left alive and one Russian, "we win." His civilian interlocutor commented sarcastically that they had better make sure that one of the Americans was a man, and the other a woman.

Years later, Thatcher said to Yazov, now the Soviet Union's last defense minister, that the great thing about nuclear weapons was that they had kept the peace. Yazov raised a bushy eyebrow, and he was right to do so: Thousands of Soviet and U.S. soldiers and millions of the local inhabitants had died in the superpowers' proxy wars in Asia, Africa and Latin America.

Let us leave the last word to a British commuter who arrived at one of the capital's main railway stations at the height of the missile crisis. Asked by a radio journalist what she thought of the whole business, she replied, "I don't know, dearie. I'm only up in London for the day."

Rodric Braithwaite is a former British ambassador to Moscow and the author, most recently, of "Moscow 1941: A City and Its People at War."