Proper noun

Singular Cold War

Plural -

Cold War

1. A period of history from 1945-1991 in which the threat of nuclear annihilation was high between the United States and Soviet Union.

The Cold War was the continuing state of conflict, tension, and competition that existed after World War II. On one side were the Soviet Union and its satellites, and on the other were the powers of the Western world under the leadership of the United States. The Cold War began in the mid-1940s and lasted into the early 1990s. Throughout this period, the conflict was expressed through military coalitions, espionage, weapons development, invasions, propaganda, and competitive technological development, which included the space race. The conflict included costly defense spending, a massive conventional and nuclear arms race, and numerous proxy wars; the two superpowers never fought one another directly.

Although the Soviet Union, the United States, Britain, and France were allied against the Axis powers during the last four years of World War II, disagreements existed both during and after the conflict on many topics, particularly over the shape of the post-war world. At the war's conclusion, most of Europe was occupied by those four countries, while the United States and the Soviet Union possessed the two most powerful military forces.

The Soviet Union created the Eastern Bloc of countries that it occupied, annexing some as Soviet Socialist Republics and maintaining others as satellite states that would later form the Warsaw Pact. The United States and various western European countries began a policy of "containment" of communism and forged myriad alliances to this end, including NATO. Several of these western countries also coordinated efforts regarding the rebuilding of western Europe, including western Germany, which the Soviets opposed. In other regions of the world, such as Latin America and Southeast Asia, the Soviet Union fostered communist revolutionary movements, which the United States and many of its allies opposed and, in some cases, attempted to "roll back". Many countries were prompted to align themselves with the nations that would later form either NATO or the Warsaw Pact, though other movements would also emerge.

The Cold War saw periods of both heightened tension and relative calm. International crises arose, such as the Berlin Blockade (1948–1949), the Korean War (1950–1953), the Berlin Crisis of 1961, the Vietnam War (1959–1975), the Cuban Missile Crisis (1962), the Soviet war in Afghanistan (1979–1989) and NATO exercises in November 1983. There were also periods of reduced tension as both sides sought détente. Direct military attacks on adversaries were deterred by the potential for mutual assured destruction using deliverable nuclear weapons.

The Cold War drew to a close in the late 1980s and the early 1990s. The United States under President Ronald Reagan increased diplomatic, military, and economic pressure on the Soviet Union, which was already suffering from severe economic stagnation. In the second half of the 1980s, newly appointed Soviet leader Mikhail Gorbachev introduced the perestroika and glasnost reforms. The Soviet Union collapsed in 1991, leaving the United States as the dominant military power, though Russia retained much of the massive Soviet nuclear arsenal.