The primary reason given by U.S. leaders to justify military involvement in Vietnam was that it would -

Which of these best explains why worldwide reactions to U.S. involvement in Vietnam grew increasingly hostile during the late 1960s and early 1970s?

The domino theory, which provided the basis for U.S. entry into the Vietnam War, was the belief that intervention was necessary to prevent -

What was the overall goal of U.S. military intervention in Vietnam from 1964-1973?