The Cold War was a period of geopolitical tension between the Soviet Union
and the United States and their respective allies, the Eastern Bloc and the
Western Bloc, after World War II. The tension stemmed from a range of
issues, including ideological differences, particularly the spread of
communism and democracy, and military buildups. The Cold War saw a
number of proxy wars, as well as the development of nuclear weapons by
both sides.
The Cold War began in the aftermath of World War II, when the victorious
Allied powers, led by the United States and the Soviet Union, divided control
of Europe along the so-called Iron Curtain. The two sides engaged in a series
of proxy wars around the globe, including the Korean War and the Vietnam
War, as well as a number of smaller conflicts.
The Cold War reached its peak in the 1960s, during the Cuban Missile Crisis,
when the Soviet Union and the United States came close to a direct military
confrontation. The two sides eventually managed to defuse the crisis and
engage in a series of arms control negotiations, which led to the reduction of
nuclear weapons.
The Cold War officially ended in 1991, when the Soviet Union collapsed and
the Cold War tensions dissipated. The collapse of the Soviet Union also led to
the spread of democracy and the end of the threat of communism.