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Washington-Moscow Hotline
Direct Communications Link · DCL

The Washington-Moscow Hotline is a Direct Communication Link (DCL) between the US and the Soviet Union, that allows the two countries to contact each other quickly in case of a crisis or a nuclear threat. The line was established in 1963, a year after the Cuban Missile Crisis that nearly led to the outbreak of a nuclear war. The hotline initially consisted of a double teleprinter link (telex), but was later replaced by facsimile units and eventually by modern computers [1].

Contrary to popular believe, the Hotline was never a red phone that could simply be picked up to speak with the leader at the other end. Although speech conversations are possible nowadays, probably using the Direct Voice Link (DVL), these links are not part of the Hotline (DCL). We are indebted to Peter Koop [1], who's excellent blog and help have inspired us to compile this page.

 Other hotlines

The idea for a hotline between the USA and the USSR dates back to 1954, when both powers realized that a direct communication line was needed in order to prevent a nuclear war. Both countries had created enormous stockpiles of nuclear weapons immediately after WWII had ended and the Cold War had begun. Both countries were also in a constant state of readiness [2].

Thousands of long-range ballistic missiles with nuclear charges were buried deep underground in silos and were carried aboard submarines. At any given moment, the world was no more than 30 minutes away from an all-out nuclear war.

Although several parties and individuals had warned the two countries, and both of them took part in the Conference of Experts on Surprise Attacks in Geneva (Switzerland) in 1958, not much happened in the following years.

The cog wheels moved very slowly during the Cold War, and military advisors at both sides didn't want their leaders to communicate directly. All that changed during the Cuban Missile Crisis of October 1962. For two weeks the world balanced on the edge of war, whilst US President John F. Kennedy had to decide whether to attack, or negotiate through alternative diplomatic channels.

Kennedy decided to take the diplomatic route, but faced serious communication issues when negotiating with the USSR. For example, it took the US ~ 12 hours to receive, decode, translate and interpret the initial 3,000 word settlement message that was sent by Soviet leader Nikita Khrushchev on 26 October 1962 at 18:00.

The next morning at 11:00 — an answer to the letter had barely been prepared — a following more agressive letter was received from the Soviet Union. Kennedy rescued the situation by ignoring the second letter, pretending he never received it, and answering the first one instead.
President John F Kennedy amidst his military advisors during the Cuban Missile Crisis in October 1962. Copyright The Daily Banter.

It worked, and the Cuban Missile Crisis came to an end. Once the dust of the event had settled, it was decided that a more direct line of communication between the US and the USSR had to be established. It would allow the leaders of the two countries to contact each other in the event of a serious threat, a malfunction or an accident. An less than a year later, the hotline was operational.

1963  Teleprinter link
Both countries recognized the necessity of creating a direct line, and after some negotiations, an agreement was signed in Geneva (Switzerland) on 20 June 1963. The link became operational less then a month later, on 13 July 1963, and was officially called Direct Communications Link (DCL). The communication link was also known by US technicians as the MOLINK (Moscow Link).

The first implementation of the hotline consisted of two full-duplex teleprinter links, one of which was a backup. Each side got two teleprinters with the Latin alphabet and two with the Cyrillic (Russian) alphabet. At each side, the lines were protected by four ETCRRM cipher machines.

Rather than using American or Russian cipher machines for the encryption of the messages, the ETCRRM machines were built in Norway by STK 1, who was considered neutral and impartial. STK delivered the machines with sufficient supplies for one year and full documentation.

The image above shows the Hotline terminal room of the NMCC at the Pentagon on 9 July 1976. Two pairs of (black) ETCRRM machines, in a mirrored arangement, are clearly visible. Each pair is accompanied by a Teletype machine for messages in the American language and an East-German T-63 2 in a wooden cabinet (at the foreground) for messages in Russian (Cryllic, see note 2) [12]. Barely visible at the extreme left, are two Siemens M-190 cipher machines that had already been installed and were under test at that time. A few years later they would replace the ETCRRMs.

As the ETCRRM is a One-Time Tape machine (OTT), it uses the principle of the One-Time Pad (OTP). When used in combination with truely random key tapes, an OTT machine is absolutely safe and unbreakable. As the Russians insisted on producing their own keys, it was decided that each side would create their own key tapes.

These key tapes were then delivered by special couriers to the embassy at the other end, who then delivered it at the other party's terminal [9]. So, the American Embassy in Moscow delivered their key tapes at the Moscow hotline terminal.

Both Latin and Cyrillic teleprinters were installed at either end, allowing each party to write in their own language. This was considered good practice, as it would avoid miscommunications and allowed some extra time for correct interpretation of the messages. The first message that was sent by the Americans on the opening day, was the well-known test message THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG'S BACK 1234567890, a line that contains all letters of the alphabet. The Soviets replied by sending a poetic description of the setting Moscow sun.

The image above shows the layout of the keyboard of the Russian teleprinter, which was in fact an East-German T-63 [12], that was delivered to the Pentagon in Washington on 26 August 1963. The image was released as a press photo by AP Wirephoto [13], with the following text:

     keyboard of a Soviet teleprinter delivered to the Pentagon in
     Washington today for use on the Washington-Moscow "hot line" of
     communications. Russian alphabet characters are on the bottom three
     lines of keys. Numbers at the top are the same as in English.
     Messages will be sent and received in both Russian and English as a
     protection against translations errors.
The physical link between the two terminals, ran from Washington to London, using the first Transatlantic Cable No. 1 (TAT-1) [5], and from there via Copenhagen, Stockholm and Helsinki to Moscow. Although the link was cryptographically safe, it was accidently cut several times, for example when a Finnish farmer accidently ploughed it up with a bulldozer [1].

Route of the landline and the radio link of the first Hotline

In London, the line was routed through a secure telephone exchange in the Kingsway Tunnels, a large underground complex. The complete route is shown in the image above. Apart from the cable link described above, there was a full-duplex radio link that was used as a backup. It ran from Washington via Tangier (Morocco) to Moscow and vice versa. This alternative route is dotted in the drawing above. It was also used for service communications. Both links were tested daily.

  1. At the time, STK was an independent subsidary of the American company ITT.
  2. It is sometimes erroneously thought that the Cyrillic T-63/SU teleprinter was made by Siemens in East Germany. This was not the case however, as there was no Siemens factory behind the Iron Curtain at the time. The T-63 was built by VEB RFT Messgerätewerk Zwönitz, but was based on the earlier RFT T-51, which in turn was an East-German copy of the Siemens T-37. The T-63/SU is also known as T63/SU12 and as T63/RU, and was able to switch between Latin and Cyrillic characters [12].

1978  Satellite links
On 30 September 1971, the US and the USSR agreed to improve the reliability of the DCL (Hotline) by giving up the radio link and installing two additional circuits: one installed by the US via the commercial geosynchronous Intelsat IV Satellite System, and other one installed by the USSR using four of their Molniya II Satellites in a high elliptical orbit. [6]. Installation and testing of the new links took several years, but finally they became operational on 16 January 1978. The new satellite links appeared to be far less vulnerable than the original cables through Europe.

At the same time the number of terminals was increased on each side, to a series of terminals at unspecified locations. In the US, there were the usual terminals at the NMCC, the ANMCC and at the White House [6]. The locations of the Soviet terminals are currently unknown. It was agreed that any messages received via the DCL would be communicated to the 'head of government'.

1980  New teleprinter equipment
In 1980, the DCL received a facelift when the Teletype terminals were replaced by newer models and the valve-based ETCRRM cipher machines were replaced by compatible solid-state Siemens M-190 units. Although the M-190 was rather old (it was developed in the early 1960s), it was relatively modern in comparison to the ETCRRM that was developed some ten years earlier. The M-190 units had been installed at the opposite wall of the room as early as 1976, and had been tested for several years before they were approved for duty and moved to the current position.

The image above shows the DCL room in the NMCC at the Pentagon. The Siemens M-190 is clearly visible in the foreground, whilst an operator is typing a message on one of the Teletype machines. The picture was taken on 2 August 1985, shortly before the next upgrade of the DCL.

1985  Facsimile equipment
On 17 July 1984, the US and the USSR signed an agreement to upgrade the DCL with facsimile equipment, following negotiations that had started in May 1983 on the initiative of President Reagan. It was agreed that identical Group III faxes, running at 4800 baud, were installed at both ends. In addition to printed text, the fax was capable of sending handwritten messages, charts, maps and photographs, and could transfer a page in 6 to 15 seconds, typically 12 times faster than a teleprinter. Mid-1985 the links became operational and were tested for several years.

At the same time, the USSR upgraded their part of the link to a newer geosynchronous Gorizont-class satellite, as a result of which the Americans no longer had to switch between Molniya satellites every four hours. In 1996, the Russians would upgrade to a new Molniya III satellite.

The image above shows the same wall of the DCL terminal room in the NMCC at the Pentagon on 14 November 1985, a few months after the 'new' facsimile equipment had become operational. The actual document scanners are on top of the shelves. Below each scanner, a standard IBM PC is installed for the One-Time Pad (OTP) encryption of the data. Documents were printed on an EPSON FX-80 dot-matrix printer. The US supplied the same equipment to the Soviets in Moscow.

In the foreground, the Siemens M-190 is still visible, although it is now at the opposite wall. The picture was taken in the same room as the previous one, as we can see the same world map and the same book shelf on the wall. For several years the old M-190 teleprinter line remained the primary link between the US and the USSR, until the fax was found reliable enough to replace it. In 1988, just before the collapse of the Soviet Union, the teleprinter link was finally shut down [1].

2007  Secure e-mail
In 2007, work started on another upgrade of the Direct Communication Link (DCL). The earlier data link was replaced by a dedicated computer network with e-mail and chat functionality. While the chat function is used by the operators for the coordination of the link, e-mails are used for the official part. The e-mail system allows text messages, scanned images and files to be sent.

At the same time, the old cable link was replaced by a new optic-fiber link, allowing the two satellite links to be used as redundant circuits. Back in 1996, the Russians had already upgraded their part of the satellite link by replacing the Gorizont satellite channel by a Molnyia III one. The upgrade became operational in 2008 and allows messages and data to be sent in near real-time.

This image was taken at the event of the 50th anniversary of the Hotline on 30 August 2013, and shows what it looks like today. The teleprinters and fax machines have made room for modern computers with secure e-mail. The man standing towards the rear is Lt. Col. Charles Cox, the senior presidential translator. Sitting in front of him is Navy Chief Petty Officer John E. Kelley, a presidential communicator. We wonder what is in the two wooden boxes at the front. Codes?

For safety reasons, there were three Hotline terminals on the American side:

  • Pentagon
    The primary terminal is at the National Military Command Center (NMCC) in the Pentagon. It is manned 24/7 in four 8-hour shifts by NMCC personnel and is under control of the Joint Chiefs of Staff. The NMCC is responsible for the daily testing of the link and for the translation of any messages that are transmitted or received.

  • White House
    Initially, there was no terminal at the White House, but when the Russians sent their first message in 1967 (at the event of the Six Day War between Egypt and Israel), Defense Secretary Robert McNamara ordered a quick patch from the Pentagon to the White House. This temporary link was later replaced by an ancillary terminal that was installed in the Military Communications Center of the White House Communications Agency (WHCA). The White House terminal has an override facility that allow it to lock-out other terminals.

  • Raven Rock Mountain
    A third terminal was located at the Alternate National Military Command Center (ANMCC), the Pentagon's backup site, located in the Raven Rock Mountain. It is operated by NMCC personnel and is tested periodically.
According to a SECRET directive of September 1985, signed by President Ronald Reagan, the President could at any time appoint new locations for additional Hotline terminals, the location of which would be classified as SECRET. Whether or not this has happened is currently unknown.

  • Moscow
    At present it is unclear what the exact location of the terminal in Moscow was. Although it was thought to be located in the Kremlin, close to the office of the Prime Minister, there are indications that it was instead opposite the Red Square at the Communist Party Headquarters [1]. Unlike in America, the Russian terminal was operated by civilians.
The Hotline was mainly intended to inform the other party in case of incidents, (nuclear) accidents and unexpected moves of fleet and troups, which the other party could see as a provocation or as an act of war. Only a few months after the DCL became operational, it was first used by the Americans on 22 November 1963, when President John F. Kennedy was murdered.

The Hotline was used during the following international conflicts:

  • 1963  Assassination of President Kennedy
  • 1967  Six Day War between Egypt and Israel
  • 1971  War between India and Pakistan
  • 1973  Yom Kippur War
  • 1974  Turkish Invasion of Cyprus
  • 1979  Russian Invasian of Afganistan
  • 1981  Threat of Russian Invasion of Poland
  • 1982  Israeli Invasion of Lebanon
  • 1991  Gulf War
  • 2003  Aftermath of Iraq War
The first official use of the Hotline by the Russians was on 5 June 1967, at the outbreak of the Six Day War between Egypt and Israel. It was the first of a total of 20 messages that were exchanged during this event. Three of these messages were related to the so-called Liberty Incident [10]; the apparantly accidental attack of the USS Liberty by the Israeli Defence Forces on 8 June 1967.

Letter by A. Kosygin to the US President via the Hotline on 5 June 1967. Declassified 7 Feb 1996.
Translated letter by A. Kosygin to the US President via the Hotline on 5 June 1967. Declassified 7 Feb 1996.

The leftmost image above shows the first message that was sent by the USSR via the Hotline, informing the US that they were seeking to end the conflict as soon as possible, and asking the US to do the same. The letter is written in Russian and is signed by Minister A. Kosygin. At the right is the official translation of the letter, created by the White House interpretors [11].

Red phone
Contrary to popular believe, the hotline was never a red phone that was used for voice (speech) communication between Washington and Moscow in the event of an emergency. Nevertheless, a typical red phone is on public display at the Jimmy Carter Library and Museum in Atlanta (USA).

The image on the right shows that particular red phone. The phone has no dial (which is common for hotline phones) and is mounted on a pole with a placard at the bottom, claiming that it was used on the Moscow-Washington hotline during the Carter Administration in the White House.

Unfortunately, the sign is wrong as this was never the case. Although it is entirely possible that the phone was used for another kind of hotline communication during the time of the Carter Administration, for example for a direct link with the Pentagon, it was definitely not used on the DCL; the Washington-Moscow Hotline.

Nevertheless, the idea of a red phone being used for hotline communication persisted, not least because of the many blockbuster movies in which the world leaders contact each other in crisis situations. For this reason, the Washington-Moscow Hotline is often referred to as the Red Phone.

There are several reasons for not having direct voice communications at times of crisis. First of all, it was very difficult, if not impossible, during the 1960s to have reliable secure voice encryption on such lines, without revealing (secret) technology. The most important reason however, is to avoid misunderstandings caused by the language barrier. Sending written messages (by teleprinter, fax or computer) allows time for proper translation and interpretation.

Direct Voice Link   DVL
Since 1990, it is possible to have a direct voice conversation with the other end, but this is not considered part of the Hotline. It is likely that for voice coversations the so-called Direct Voice Link (DVL) is used. This link has terminals at both ends near the offices of the Presidents and is routed (multiplexed) over the same satellite links as the DCL. The DVL is normally used for diplomatic and scheduled traffic, but can be used in crisis situations by special arrangement.

Video conferencing
In 2008, the DVL was integrated into a secure digital computer network, which has since been expanded with video conferencing capabilities. The first video call between US President Joe Biden and his Russian counterpart President Vladimir Putin took place on 7 December 2021 [21].

Although Puting and Biden had been in video con­ferencing calls before, this was the first time it took place on the bilateral communication link between the two nations. According to Russian press agency TASS, the call lasted for nearly one hour, during which the two leaders spoke about the situation in Ukraine, NATO's eastward expansion, strategic stability and other bilateral issues, such as the situation in Afganistan [22]. The conference took place behind closed doors.   

The image above was was published by The White House and was taken on 7 December 2021 in the Situation Room, at the start of the first video call between Biden and Putin. Remarkably, the feat was barely picked up by western media, probably because it was not recognised as a first.

Also in the Situation Room besides US President Joe Biden were National Security Advisor Jake Sullivan, secretary of State Antony Blinken and Eric Green, a senior advisor on Russia [21].

The conference call took place at the initiative of Russian President Vladimir Putin, who was at the time at his summer residence Bocharov Ruchei, in the Black Sea resort of Sochi. The photograph shown on the right was taken that day and was released by the Kremlin.

 More on this topic (off-site)


Government-to-Government Communication Link   GGCL
On 15 September 1987, close to the fall of the Soviet Union and subsequently the end of the Cold War, both the USA and the USSR established a so-called Nuclear Risk Reduction Center (NRRC) in order to build confidence through information exchange about their nuclear arsenals [15].

This was done as part of a series of Confidence Building Measures (CBMs), and came online on 1 April 1988. For the information exchange about the nuclear programs, a direct communications link was established, that resembled the Hotline.

Initially, this link consisted of teleprinters with one-time tape encryption, but these were later replaced by facsimile equipment (fax) that used IBM PCs for the one-time pad encryption. In late 1995, the NRRC moved to secure e-mail with an additional chat channel for coordination. The video on the right features the American NRRC.

After the fall of the Soviet Union in 1991, the line between the USA and Russia remained active and was extended to Ukraine, Belarus and Kazakhstan. It is officially known as the Government-to-Government Communications Link (GGCL). In the US, the NRRC is the responsibility of the US Department of State (DoS). The video above shows what the US NRRC looked like in 2012 [17].

Cybersecurity Link
On 17 June 2013, it was announced that during the 39th G8 summit in Northern Ireland 1 , the United States and Russia had agreed upon several new Confidence Building Measures (CBMs), in order to reduce the danger from cyber security threats that appear to originate in both countries.

The information is exchanged regularly between US-CERT 2 and its counterpart RU-CERT 3 , and consists of technical information about malware and other kinds of risks to critical infrastructure, that appears to originate from the other side and could be misinterpreted as an attack (act of war).

US-CERT is part of the National Cybersecurity and Communications Integration Center (NCCIC), which falls under the responsibility of DHS, the US Department of Homeland Security. The image on the right shows the Watch Room of the NCCIC during the tenure of U.S. President Obama [19].

This so-called cybersecurity link followed hot on the heels of the revelations of NSA/CIA whistle­blower Edward Snowden in early June of 2013, that had greatly embarrassed the US Government. In the image, several secure STE phones are clearly visible on the desks. It is believed that the STE was also present at the Russian side of the link. It has since been replaced by IP-based phones. The actual establishment and maintenance of the cybersecurity link was delegated to the NRRC, which already operated a reliable link between Washington and Moscow, the so-called GGCL.

Shortly before the US presidential election of 2016, (then) President Barack Obama warned the Russian Government not to interfere with the election process by means of hacking operations. According to some press reports, he used the 'Red Phone' for this, but it is unclear whether he used the Direct Voice Link (DVL), the NRRC's Government-to-Government Communication Link (GGCL), the Cybersecurity Link, the Foreign Affairs Link (FAL) or the actual Hotline itself [16].

  1. Held on 17 and 18 June 2013, at the Lough Erne Resort in County Fermanagh in Northern Ireland (UK).
  2. US-CERT = United States Computer Emergency Readiness Team, also known as the United States Computer Emergency Response Team.
  3. RU-CERT = Russian Federation Computer Emergency Response Team.

US-Russia communications links
The following official communications links between the US and Russian are currently known:

ANMCC   Alternate National Military Command Center
Backup command center of the Pentagon, also the backup terminal of the Hotline (DCL), located in Raven Rock Mountain. (Wikipedia)
DCL   Direct Communications Link
Official name of the Washington-Moscow Hotline. (Wikipedia)
DHS   Department of Homeland Security
DVL   Direct Voice Link
Voice communication link, running on the same network, but not part of, the Hotline.
GGCL   Government-to-Government Communication Link
Direct encrypted e-mail link between the USA, Russia, Ukraine, Belarus and Kazakhstan, managed by the NRRC of each country.
NCCIC   National Cybersecurity & Communications Integration Center
US body for the protection of information and cybersecurity. Part of the Department of Homeland Security (DHS).  Website
NMCC   National Military Command Center
Responsible for operation, maintenance and testing of the Hotline (DCL). Also the primary terminal of the US side of the Hotline. Located at the Pentagon in Washington. (Wikipedia)
NRRC   Nuclear Risk Reduction Center
Official bodies of the USA and of the former USSR, established on 15 September 1987, to reduce the risk of a potential nuclear war, an to inform each other of possible threats.  More
WHCA   White House Communications Agency
Official communications agency of the White House. Also responsible for operating the secundary terminal of the US side of the Hotline (DCL). (Website) (Wikipedia)
  1. Peter Koop, The Washington-Moscow Hot Line
    Electrospaces blog. Retrieved January 2013.

  2. Matt Dattilo, Washington-Moscow Hotline Established, June 20, 1963
    21 June 2011. Retrieved January 2013.

  3. AP, Photograph of Siemens M-190 and teletypes in the Hotline room
    27 August 1985. Retrieved November 2012. Image kindly supplied by [1].

  4. Scott Davis, Images of Us-Soviet Hotline
    © Time Inc. LIFE magazine, 14 November 1985, Arlington, VA, USA.
    Retrieved January 2013.

  5. Wikipedia, TAT-1, Transatlantic Cable Number 1
    Retrieved Januari 2013.

  6. Ronald Reagan, National Decision Directive Number 186
    4 September 1985. SECRET. Declassified 10 June 2011.

  7. US Department of State, Agreement Between the USA and the USSR to upgrade the DCL
    17 July 1984. Retrieved January 2013.

  8. Dan Merica, If these Walls Could Talk: Installing a direct line to Moscow
    CNN Politics website, 27 August 2012.

  9. Hugo Ryvik, Thales, On a Secret Mission. 50 years of Norwegian cryptology.
    Thales, private publication, 2005.

  10. A. Jay Cristol, The Liberty Incident
    July 2007. Retrieved Januari 2013.

  11. NARA, Letter from A. Kosygin to the US President via Soviet Molink
    5 June 1967. Confidential. Declassified 7 February 1996. Translation...

  12. Joachim Beckh, Blitz & Anker, Band 1: Informationstechnik - Geschichte und Hintergründe
    Backgrounds on the T-63 teleprinter (German). ISBN 3-8334-2996-8. p. 119.

  13. AP Wirephoto, Image of Russian keyboard
    26 August 1963. AP Wirephoto #b21455kwg. Crypto Museum archive #CM301762.

  14. US Army, Hotline, now 50 years old...
    Website. Retrieved September 2013.

  15. USA/USSR, Announcement about the establishment of NRRCs
    Agreement between the United States of America and the Union of Soviet Socialistic Republics on the establishment of Nuclear Risk Reduction Centers (and protocols hitherto). 15 September 1987.

  16. Peter Koop, Obama used a cybersecurity link for the first time to warn Russia
    29 December 2016, updated 7 January 2017.

  17. US DoS, Inside the U.S. Department of State: Nuclear Risk Reduction Center
    Via YouTube. 24 October 2012.

  18. US-Russian Cooperation of Information and Communications Technology Security
    The White House (under Obama), Office of the Press Secretary, 17 June 2013.

  19. Jim Watson, Image of the Watch Center of the NCCIC
    AFP/Getty Images. Retrieved June 2017.

  20. UPI, Image of ETCRRM cipher machines and T-63 teleprinters
    9 July 1976. Retrieved November 2012. Image kindly supplied by [1].

  21. Peter Koop, From the Hotline to the first video call between presidents Biden and Putin
    Electrospaces blog, 21 December 2021 (updated 19 March 2022).

  22. TASS, Putin-Biden video conference over
    7 December 2021.
  1. Thanks to Jim Meyer for pointing this out.

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Crypto Museum. Created: Sunday 27 January 2013. Last changed: Saturday, 06 August 2022 - 09:50 CET.
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