Answer: b. fear of communism spreading to many Asian countries
Explanation:
By the mid-1950s, cold war ideology had led American officials to presume that the United States must thwart every act of Communist insurgency or aggression around the world. In 1954, Eisenhower used what he called the “falling domino” theory to explain why the United States needed to repulse Vietnamese communism: “You have a row of domino set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly.” If South Vietnam were to succumb to Communist insurgency, he predicted, the rest of Southeast Asia would soon follow.
