Answer: The United States engaged in an ideological "cold war" against the international spread of Communism.
Explanation:
Communism became the most significant new political movement of the twentieth century. The tense ideological contest with the Soviet Union and Communist China produced numerous foreign crises and sparked a domestic witch hunt for Communists in the United States that far surpassed earlier episodes of political and social repression. This assumption eventually embroiled the United States in a costly war in Southeast Asia that destroyed Lyndon B. Johnson’s presidency.
