It is impossible for this writer to pen a history of the Cold War (war without heated conflict) in 500 words, so please forgive my inadequacies. The Cold War, like so many actions, is wrought in fear. After World War II, the USA and other nations feared the expansion of communism. It also wasn’t very “cold.” For example, the Korean War and the Vietnam War were two wars that involved U.S. troops. Oh, and let’s not forget the skirmishes in Afghanistan, and remember the Bay of Pigs? So, the Cold War wasn’t really cold; then why all the conflict—fear of Communism upsetting our Republic. In World War II, the U.S. showed the destructive power of atomic weapons, and the prediction by George Orwell that the world would end in a nuclear holocaust was looming.
The alliances loosely threaded together during WWII were unraveling. Russia tightened its influence over Eastern Europe by assisting with the establishment of communist governments in nations that had been previously overtaken by Germany. The Soviets were intent on spreading communism throughout the world. Through fear of communism, the U.S. developed guidance and policy through the Truman Doctrine and the Marshall Plan (European Recovery Plan). President Truman established, through Congress, that the United States would provide political, military, and economic assistance to all democratic nations under threat from external or internal authoritarian forces. The Marshall Plan, enacted in 1948, allocated $15 billion to help finance the rebuilding efforts of Eastern and Western Europe. This effort was intended to help prevent the expansion of communism in Europe.
During the peak of the Cold War, the Soviets attempted to blockade Germans from commuting between east and west Berlin; then, shortly afterward, in a show of strength, they exploded their first atomic bomb (1949). This is when the U.S. and its European Allies formed the North Atlantic Treaty Organization (NATO). By the mid ‘60s, both the USSR and the U.S. had developed intercontinental ballistic missiles with nuclear warhead capabilities, and Russia placed the missiles in Cuba with targets of U.S. cities. Neither the Soviets nor the Americans were ready to use nuclear weapons resulting in the Soviets removing the missiles. Discussions between the superpowers ultimately led to the Nuclear Test-Ban Treaty of 1963. Even so, the next 25 years were spent with nuclear arms buildup in both nations.
While the Soviets sent troops to preserve communist rule (east Germany 1953, Hungary 1956, Czechoslovakia 1968, and Afghanistan 1979), the U.S. helped to overthrow left-wing governments (Korea 1950-53, Guatemala 1954, Cuba 1961, Dominican Republic 1965, Vietnam 1964-75, and Grenada 1983). By the 1960s, China and Russia ended their political relationship, and western Europe and Japan were achieving significant economic growth. Smaller nations were asserting political and economic independence with less superpower coercion. Another failed attempt to limit an arms buildup resulted in the Strategic Arms Limitation Talks (SALT I  and II ).
The ever-present threat of nuclear annihilation induced fear into domestic life. At-home bomb shelters were constructed, attack drills were practiced at schools, and Hollywood created nuclear devastation films. In 1989, President Reagan stood at the Brandenburg Gate in Berlin and stated, “Mr. Gorbachev, tear down this wall.” The Berlin wall came down, and in late 1991, the Soviet Union collapsed. The Cold War had come to an end.