The US and Russian leaders often communicate by phone
One of the most potent symbols of the Cold War era - the telephone hotline linking the Kremlin and the White House - is 40 years old this month.
To mark the occasion, Russian television interviewed an official translator and a Kremlin aide who witnessed its use.
The hotline, called the "red telephone" in Russian, was set up in 1963 after the Cuban missile crisis had brought the world to the brink of nuclear war.
During the crisis, US President John F Kennedy and Soviet leader Nikita Khrushchev were obliged to negotiate through intermediaries.
The line was used for the first time in 1967, during the Six Day War between Israel and its Arab neighbours.
USSR Prime Minister Aleksey Kosygin, KGB chief Yuri Andropov and Foreign Minister Andrei Gromyko were called into the Kremlin basement where the hotline apparatus was located for talks with US President Lyndon B Johnson.
A real telephone was only installed in the 1970s
The translator present at the time, Viktor Sukhodrev, who served three Communist Party general secretaries, told Russian TV of Mr Kosygin's surprise when he discovered that the hotline was not actually a telephone.
"How are you meant to get in touch?" he remembers the Soviet leader asking.
"There was no telephone, just the basic tele-typewriters that you'd find in any telegraph office," Mr Sukhodrev added.
The Soviet leaders had to wait while their text was translated and sent down the line to Washington by operators.
"The mere appearance of Kosygin, Gromyko and Andropov caused great alarm among the translators and operators, who had never seen such eminent leaders," Mr Sukhodrev said.
"Their hands were shaking while they transmitted it all to Washington."
The teletypewriters were replaced by a real telephone during Leonid Brezhnev's long rule in the 1970s.
Brezhnev told Carter that no Afghan invasion was planned
But the advance in technology did not automatically increase trust between the two sides.
Former Kremlin aide Fedor Burlatskiy recalls the occasion when President Jimmy Carter rang to ask Mr Brezhnev if it was true that the USSR was readying troops for an invasion on the Afghan border in 1979.
"Really? I hadn't heard. Let me ask the defence minister," Mr Burlatskiy remembers Mr Brezhnev saying.
The Soviet leader then pretended to ask his defence minister before finally replying: "The minister here says no such thing is going on."
Times may have changed, but the hotline still plays an important role.
"Today, Vladimir Putin and George Bush are discussing plans for the peaceful restoration of Iraq after another war in the Middle East," the TV said.
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