In his desperate search for a gesture that would reverse the downward spiral of Soviet-American relations, Fulbright embraced the notion of a comprehensive test ban treaty. He was convinced that such a pact was both technically and politically feasible. An easing of the arms race was manifestly in Khrushchev and the Soviet Union's interests. Even assuming that Khrushchev and his fellows in the Kremlin were the paranoid, xenophobic creatures that many Kremlinologists portrayed them as, Fulbright reasoned, the best method for dealing with them was to build trust, not engage in confrontation.

In the wake of the Cuban missile crisis, Kennedy and his advisers sensed a slight thaw in Soviet-American relations. The Russians had made good on their promise to allow the U.S. Navy to inspect ships carrying dismantled missiles out of the Ever Faithful Isle. In 1963, as a result of the Cuban confrontation, Kennedy and Khrushchev agreed to an emergency phone and teletype, or “hot line,” connection between Washington and Moscow. It provided instant communication between the heads of the two superpowers when one or the other feared miscalculation in a crisis. Walt Rostow and Jerome Weisner, Kennedy's science adviser, both of whom had been American delegates to the 1960 Pugwash Conference, a privately funded international meeting designed to reduce the chances of nuclear war, urged the president to make a test ban treaty part of detente. In March 1963 Kennedy authorized his arms control representatives in Geneva to begin discussions in earnest on a treaty and in June announced that the United States would no longer test nuclear arms in the atmosphere “so long as other states do not do so.”