The Cold War was a period of tension and subdued hostility which gripped most of the world between the 1940s and the early 1990s. The primary actors in it were the United States and its allies, countered by Russia and countries aligned with that nation. Rather than engaging in a potentially devastating out and out war, the countries involved in the Cold War jockeyed for position in more subtle ways. Many major events in global history including the rise of the Berlin Wall and the Cuban Missile Crisis were related to this war.
The Cold War has its roots in the Second World War, when the Allied powers made an uneasy pact with Russia to defeat Germany and Italy. The Allied countries were concerned about joining forces with a Communist nation, and Russia was likewise hesitant about the agreement. After the Second World War, Germany was divided into territories occupied by the Allies and Russia, and the relationship started to go sour shortly after that.
From the point of view of the West, Communist was a dangerous idea. Russia had firm control of Eastern Europe, but the Allies and the United States in particular hoped to prevent the spread of Communism through containment. The West was also concerned about the potential for conversion in developing nations in Africa, Asia, and South America. The West heavily controlled regions which bordered Communist countries, and sent a variety of spies across the borders to gather information about Communist regimes. In addition, both Communists and Westerners engaged in wars on other ground, such as in Korea and Vietnam, in an attempt to gain the upper hand.
Russia and allied nations such as China, on the other hand, wanted to protect themselves and the Communist nations that they were allied with. The division between Communist Eastern Europe and the West was called the “Iron Curtain,” due to the difficulty in crossing it, thanks to Communist officials trying to keep citizens in and Westerners out. Communist nations competed with the West economically, scientifically, and technologically in an attempt to establish superiority. The Cold War led the Space Race which landed Americans on the moon in 1969, and it also led to nuclear proliferation, as a growing number of countries grew concerned for their safety.
Numerous attempts were made at reaching a diplomatic agreement during the Cold War, but the Cold War truly began to end when Eastern European nations rose up against Communism. The Solidarity anti-communist movement gained ground in Poland as the Berlin Wall fell and leaders of the United States and Russia started to engage in cooperative talks. Diplomatic relationships between the major players were re-established in the 1990s, to the relief of many people around the world who had been impacted by the Cold War.