Boston ? Caroline Kennedy and Sergei Khrushchev met at the John F. Kennedy Library on Sunday, 40 years after the Cuban Missile Crisis, in a 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. They did not speak to the media about their meeting.

About 850 people attended a forum discussion that included Khrushchev, former Kennedy advisers Arthur Schlessinger Jr. and Theodore Sorensen, and Josefina Vidal, the First Secretary of the Cuban Interest 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.

Sergei Khrushchev, left, and his wife, Valentina Golenko Khrushchev, meet with Caroline Kennedy at the John F. Kennedy Library in Boston. Sunday was the first meeting between the children of the two men who in 1962 narrowly averted a nuclear confrontation during the Cuban Missile Crisis.

He compared the defense of Cuba to the American commitment to defend West Berlin. He said both superpowers needed to assure their allies they were serious in their commitments.

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.