Caroline Kennedy and Sergei Khrushchev met at the John F. Kennedy Library today, 40 years after the Cuban Missile Crisis, in what organizers called "the first meeting between the children of the men who in 1962 saved the world from a nuclear world war."

Their fathers, President Kennedy and Soviet leader Nikita Khrushchev, were at the center of the Cuban Missile Crisis, a moment historians believe was the closest the world has come to nuclear war.

"It was quite emotional to realize that when our fathers transformed the hours of danger into the beginnings of a process for peace, they did it for us and for all children threatened by a world at war," Caroline Kennedy said.

The two viewed documents and letters exchanged between their fathers during the crisis and examined a copy of the 1963 Nuclear Test Ban Treaty signed by their fathers that had been kept by Caroline's mother, Jacqueline Kennedy Onassis.

They did not speak to the media about their meeting.

About 850 people attended a forum discussion that included Khrushchev, former Kennedy advisers Arthur M. Schlessinger Jr. and Theodore Sorensen, and Josefina Vidal, the first secretary of the Cuban Interests Section in Washington, the official voice of the Cuban government in the United States.

Sergei Khrushchev said his father decided to send missiles to Cuba because he felt an obligation to defend it. He compared the defense of Cuba to the U.S. commitment to defend West Berlin. He said both superpowers needed to assure their allies they were serious in their commitments.

He also said Kennedy and his father's negotiations "showed that they trusted each other."

The crisis began when President Kennedy learned that Cuba had Soviet nuclear missiles capable of reaching the United States. Days later, he ordered a naval blockade of Cuba.

The crisis ended two weeks later when Khrushchev promised to remove the nuclear missiles in exchange for a promise by Kennedy not to invade Cuba. The United States also agreed to remove U.S. missiles from Turkey, a Soviet neighbor.

Schlessinger said "the Cuban Missile Crisis was the most dangerous moment of the Cold War. It can be argued further that it was the most dangerous moment in human history."

Schlessinger said never before had two opposing powers had the technical ability to destroy the world. "We're lucky to have survived it," he said.

Caroline Kennedy, left, shows a copy of the 1963 Nuclear Test Ban Treaty to Sergei Khrushchev, right, son of ex-Soviet leader Nikita Khrushchev.