Following the October 1962 Cuban Missile Crisis, in which the U.S. and U.S.S.R had come dangerously close to all-out nuclear war, John F. Kennedy becomes the first U.S. president to have a direct phone line to the Kremlin in Moscow. The tense diplomatic dialog that was engaged in during the crisis was painfully slow due the banal communication system in place. Indeed, the USSR and America were literally “On the Brink” during this crisis, which was resolved peacefully.
President Kennedy and Premier Khrushchev both signed a nuclear test-ban treaty on August 5, 1963, and mutual fears of future "misunderstandings" led to the installation of an improved communications system.
By today’s standards the system is archaic, but when implemented in 1963 was considered revolutionary and much more reliable than the regular trans-Atlantic phone call, which was routed between several countries before it reached the Kremlin.
The first U.S. president to use the new system was President Lyndon B. Johnson in 1967. He notified Soviet Premier Alexei Kosygin that he was considering sending Air Force planes into the Mediterranean during the “Six Day War”.