Final answer:
The Cold War was a political, military, and economic rivalry between the United States and the Soviet Union from 1945 to 1991. It involved proxy wars, an arms race, and the development of nuclear weapons.
Step-by-step explanation:
The Cold War was a decades-long political, military, and economic rivalry between the United States and the Soviet Union from 1945 to 1991. Although it did not involve direct military conflict between the two superpowers, it had far-reaching effects on the world. Both sides sought influence and control over other countries, leading to numerous proxy wars and an arms race, including the development of nuclear weapons.