In 1957 the Soviet satellite Sputnik 1 was successfully launched into orbit.

In 1953 an armistice was agreed that established a new border close to the 38th parallel. In 1951, China, another communist nation, sent troops in support of North Korea, and the two sides reached a stalemate. The United Nations quickly arranged support for the south, and troops from the U.S., U.K., Australia, Canada, India, New Zealand and South Africa, among others, were sent to oppose North Korea. On June 25, 1950, North Korea, with support from the USSR (including covert operations and providing aircraft and medical support), invaded South Korea. At the end of World War II, Korea, a former territory of Japan, was divided along its 38th parallel, and an internal border was established between the communist North Korea backed by the Soviet Union and the Western-leaning South Korea, according to the Imperial War Museum. The first hotspot of the Cold War, when the two sides came into military conflict - albeit indirectly - was the Korean War, which took place between 19.

Men of the 187th US Regimental Combat Team prepare for battle during the Korean War (Image credit: Getty/ Hulton Archive)

Why was it called the cold war