THE RED PHONE
During a visit to China in March 2007, Chairman of the Joint Chiefs of Staff General Peter Pace announced that Washington and Beijing were considering installing an emergency hotline between the leaders of the two countries. Such hotlines tend to be known as "red phones," after the U.S.-Russia link established in 1963, following the potentially disastrous failures of communication during the Cuban missile crisis. (For example, it reportedly took the U.S. c.12 hours to receive and decode Khruschev's first settlement message, and the Soviet ambassador later disclosed that he handed messages to a bicycle courier, who in turn sent them via Western Union.) The "red phone" was actually used for the first time in 1967, when it helped prevent the Six Day War from escalating into a global conflict.
Initially, the "red phone" consisted of a set of teleprinters connected via transatlantic cable. In the 1970s, the teleprinters were replaced with actual phones and, later, satellite communications and facsimile transmission. Why the phone is "red" is the subject of some speculation. Moscow apparently called their side of the connection "the red telephone"--though whether this was because of its actual color, the urgency of its function, or a humorous allusion to political ideology, is unclear.
Thomas Edward Brown (1830-97)