Final answer:
The Cold War was a prolonged period of political and military tension between the USA and the USSR, emerging after World War II due to ideological differences and competition for global dominance, which played out in various indirect conflicts but never as direct warfare.
Step-by-step explanation:
After the end of World War II, the alliance between the USA and the USSR would soon change, leading to a period known as the Cold War, which lasted from 1945 until the Soviet Union's collapse in 1991. The USA and the USSR emerged as the two major superpowers, directly opposing each other ideologically, with the United States supporting democracy and capitalism, and the Soviet Union advocating for communism. This competition played out globally through various means such as economic aid, military assistance, and technology advancements, without turning into direct military conflict between the two nations, but profoundly affecting global politics and society.
The root of this era's tension lay in the competing ideologies and visions for the future of the world. While there were several flashpoints, like the Blockade of West Berlin and the spread of communism in Asia, the underlying cause of the Cold War was the struggle between the USA and the USSR for global influence and power. The period was marked by an arms race, proxy wars, the space race, and the establishment of opposing military alliances like NATO and the Warsaw Pact.