The President Johnson believe that it was important for the United States to win in Vietnam because he believed in the domino theory. Option D is correct.
What is domino theory?
After World War II, the United States accepted the domino theory, which stated that the “fall” of a non-communist state to communism would hasten the fall of non-communist governments in neighboring states.
President Johnson believe that it was important for the United States to win in Vietnam by making the use of domino theory.
The domino theory is very important because it contributed to the U.S. into the war on the side of South Vietnam to assist them in defeating the communist troops of North Vietnam.
That were receiving support from the Soviets and the Chinese.
Therefore, option D is correct.
Learn more about the Vietnam War, refer to:
https://brainly.com/question/11375126
