Why did the American president start the Vietnam war?

Answer 1

The American involvement in the Vietnam War escalated primarily due to the Cold War context, with the U.S. aiming to prevent the spread of communism in Southeast Asia. The Gulf of Tonkin incident in 1964, where North Vietnamese forces allegedly attacked U.S. naval vessels, provided a catalyst for President Lyndon B. Johnson to increase military engagement. The belief in the "domino theory," which suggested that the fall of one Southeast Asian country to communism would lead to the fall of its neighbors, further justified U.S. intervention. Ultimately, the decision to escalate was driven by a combination of ideological, geopolitical, and security concerns.