What promoted the US to enter into a war in Vietnam?

Answer 1

The United States entered the Vietnam War primarily to prevent the spread of communism in Southeast Asia, guided by the "Domino Theory," which suggested that if one country fell to communism, neighboring countries would follow. U.S. involvement escalated after the Gulf of Tonkin Incident in 1964, where alleged attacks on U.S. naval vessels by North Vietnamese forces led Congress to pass the Gulf of Tonkin Resolution, granting President Lyndon B. Johnson broad military powers in Vietnam. Additionally, the desire to support the South Vietnamese government against the communist North was a crucial factor in America's commitment to the conflict.