What was the Red Phone?
The Red Phone, also known as the Red Telephone, the Moscow-Washington hotline and the Hot Line, is a "confidence building measure" and communications system designed to decrease tensions and prevent accidental nuclear war by providing direct contact between the leaders of the United States and Russia. It links the White House (via the National Military Command Center) with the Kremlin.
This hotline was established in 1963 and links the Pentagon with the Kremlin (historically, with Soviet Communist Party leadership across the square from the Kremlin itself).
Although in popular culture it is known as the "red telephone", the hotline was never a telephone line, and no red phones were used. The first implementation used Teletype equipment, and shifted to fax machines in 1986.
Since 2008, the Moscow–Washington hotline has been a secure computer link over which messages are exchanged by a secure form of email.