Why did the United States join the North Atlantic Treaty Organization in 1949?

The United States joined NATO in 1949 as part of a collective defense alliance formed in response to growing tensions with the Soviet Union after World War II. Member nations agreed that an attack on one would be treated as an attack on all, helping deter Soviet aggression and the spread of communism. Thus, the correct choice is “to protect against the Soviet Union and the spread of communism.”

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