To what Extent Did Khrushchev Reduce Tension in 1953-1960?

Khrushchev was the leader of the Soviets after the death of Stalin and a short struggle for power with Malentov. He was thought to be a man the Americans could try to approach because he used a great number of methods to try to reduce the tension between the USSR and the US. These methods included proposing summit meetings, destalinization, proposing peaceful co-existence, halting the testing of nuclear devices. However the success of Sputnik made the Americans once again paranoid and afraid of the Soviets. Did Khrushchev really succeed in the détente between the Soviets and the US, and to what extent did he success?
Politically, during Khrushchev's "secret speech" at the Twentieth Congress of the C.P.S.U. in 1956, he openly attacked Stalin. "Stalin, using his unlimited power, allowed himself many abuses, acting in the name of the Central Committee, not asking for the opinion of the Committee members nor even the members of the Politburo, or even inform them...…