Cold War

The Cold War was a term used to denote the tensions between the Capitalist nations of the world (particularly the United States and the United Kingdom) and the Communist nations of the world (particularly the Soviet Union) in which, though the tensions were high, no actual fighting occurred. The east and west were, according to the Eleventh Doctor, "standing on the brink of nuclear oblivion." Both sides could easily have destroyed the other. (TV: Cold War)

A day to come
In 1903, after receiving a wealth of information from the future, Grigori Rasputin foresaw the Cold War. (AUDIO: The Wanderer)

During World War II, when it appeared that the United Kingdom would be invaded by Nazi Germany, four citadels were built under the surface of London. They were intended to allow the British government to continue operations if the worst happened. After the war, the citadels were maintained due to the threat posed by the Soviet Union in the Cold War. (AUDIO: The Fifth Citadel)

Cold conflict
The Doctor took part in some events of the Cold War. The Eighth Doctor was blackmailed by Kim Philby into assisting him against the Players in 1951, whilst his seventh incarnation held Majestic clearance with the United States in 1957. (PROSE: First Frontier, PROSE: Endgame)

The Tenth Doctor made reference to the Cold War during a visit to New Mexico in 1958. Cassie Rice used the Cold War slang "Reds" to refer to Russians. (TV: Dreamland)

The Jalaphron tried to end the Cold War in 1962 by starting the Cuban Missile Crisis. (PROSE: Checkpoint) 1962 was remembered by the Daleks as a flashpoint in the Cold War. (GAME: Planned Obsolescence)

In October 1963, Susan Foreman read an article about the Cold War in The Daily Sketch. She had never previously heard of the conflict. (AUDIO: Hunters of Earth)

On November 23rd, a group of Russian spies including Miles Barrington Smythe, aided by MI6 double agent Barker, operated in London. (TV: The Cambridge Spy)

In Краснодар, a town in Caithness, British soldiers were trained for an invasion of the Soviet Union during the 1980s. (TV: Before the Flood)

In 1983, the Ice Warrior, Skaldak, tried to end the Cold War by launching the submarine launched ballistic missiles from the Soviet Delta-class ballistic missile submarine, the Firebird, which could have caused both the East and the West to annihilate each other in mutually assured destruction. He was stopped when an Ice Warrior ship rescued him. (TV: Cold War) 1983 was also regarded as a Cold War flashpoint by the Daleks. (GAME: Planned Obsolescence)

The Cold War had ended by 1993. (PROSE: Goth Opera) However, there were two unnamed power blocs poised to annihilate each other again by 2084. (TV: Warriors of the Deep)

Projects and plans
During the Cold War, there were plans to build an underground headquarters for the British government in the event of a nuclear war. (TV: Invasion of the Dinosaurs)

At one point, to avoid warfare, the three superpowers, America, China and Russia gave their destructor codes to Great Britain. (TV: Robot)

During the Cold War, the British army trained for an invasion of Russia in towns that were made to look like Russian villages. One such town in Caithness, Scotland was flooded by the Twelfth Doctor to kill the Fisher King. (TV: Before the Flood)

The Golgotha Project was formed during the war. (PROSE: Heart of TARDIS)

One of the Tycho Project's telescopes, located in Goblin's Copse in England, was used as a listening station during the Cold War. (TV: The Last Sontaran)

The Space Race
During the Cold War, the USA and the USSR raced to develop rockets and space technology. To the general public, it looked like the USSR was having much of the success. The dog Laika was the first animal to orbit the Earth, and Yuri Gagarin was the first man in outer space. In actual fact, the United States were secretly much further ahead. By November 1963, Moonbase Eisenhower had been established on the lunar surface. It's purpose was to sustain a viable human population in the case of nuclear war. It was destroyed on the 23rd November, after being discovered by the Sixth Doctor. Six years later, the USA presented the Apollo 11 Moon Landing as Earth's first steps on the Moon as a publicity stunt for Earth and the wider universe. (AUDIO: 1963: The Space Race)

Later history
A group of Grey Daleks active under a Gold Dalek in the 52nd century plotted to use the Cold War against humanity, with one Grey Dalek suggesting the flashpoints of 1962 or 1983. The Daleks' plot to make humanity destroy itself in thermonuclear war were thwarted by the Seventh Doctor and company. (GAME: Planned Obsolescence)

Parallel Universes
In one parallel Germanian universe, America and the Nazis had been locked in a stalemate for several years, and President "JPK" was reaching out to Hitler for negotiations. (PROSE: Warlords of Utopia)

Behind the scenes

 * Both Invasion of the Dinosaurs and Robot imply that the Cold War was already over at the time those stories took place. However, in the novel Goth Opera, by Paul Cornell, it is noted by Tegan Jovanka, who comes from the year 1981, that the Cold War had ended by 1993.
 * In real life, the production of the entire classic series was during the Cold War. There is no official end to the Cold War, although one of its possible endpoints, the fall of the Berlin Wall, occurred on 9 November 1989. Little more than a month later, Doctor Who broadcasted its last episode.