Answer:
Soon after the end of the Second World War, an arms race began between the USA and NATO, founded in 1949, on the one hand and the Soviet Union and the Eastern Bloc on the other. Above all, it was about the development of more effective nuclear weapons. In the end, the rivalry exhausted the USSR's economy so much that it hastened its disintegration.
This arm race began during World War II, with American project Manhattan in early 1945. The Soviet Union acquired the technology for the production of nuclear bombs in 1949. The next phase, for which there was a specific increase in the power of nuclear weapons, lasted until the early 1960s.
The arms race between the United States and the USSR was partially dampened by some mutual disarmament efforts. One of the first major treaties between these powers is abbreviated SALT (Strategic Arms Limitation Talks) and took place in 1969. Later efforts to disarm each other can be attributed to President Ronald Reagan in the mid-1980s.