"The Cuban missile crisis also had beneficial consequences. The close brush with nuclear war helped create a climate for productive arms control negotiations, which had not existed since the abortive Paris summit of May 1960. Attempting to reduce tensions with the West, Krushchev, on December 19, 1962, sent Kennedy a personal letter inviting him to intensify the effort to conclude a nuclear test ban treaty. With the humiliation of the Bay of Pigs fiasco erased by his astute performance during the Cuban missile crisis, and sobered by the close superpower approach to nuclear war, Kennedy accepted Krushchev's invitation. Six months later, Kennedy delivered the most conciliatory speech on the Soviet Union of his career. In a commencement address at American University on June 10, 1963, he called on Americans to reexamine their attitudes toward the Soviet Union. "In the final analysis," he told his audience, "we all inhabit this small planet... And we are all mortal." Kennedy called on the American people to support his effort to conclude a nuclear test ban agreement. It would be an initial step toward preserving the life of the planet. As a sign of good faith in the ultimate success of the test ban talks, Kennedy announced that the United States would not conduct atmospheric nuclear tests as long as the Soviet Union employed similar restraint."