Why do some historians criticize the United States' decision to send combat troops to Vietnam after the Gulf of Tonkin incident?

A.It is likely that the South Vietnamese could have won the war if the United States had remained in an advisory role.

B.Evidence suggests that the reported North Vietnamese attack on an American naval vessel may never have happened.

C.Americans of the era feared that Vietnam would turn to Communism if left alone, but today's historians do not think that would have happened.

D.The Communist Party of the United States of America gained dominance at home while the military focused its efforts overseas.

Some historians criticise the United States decision to send combat troops to Vietnam after the Gulf of Tonkin incident because the evidence suggests that the reported North Vietnamese attack on an American naval vessel may never have happened.

Explanation:

There is room to believe after the interpretation of strong evidence available, that the help provided by the American navy to South Vietnam to find the radars of the North Vietnamese Army off its coast, provoked the North Vietnamese defence to attack the United States Naval vessel.
If the United States had stayed in the role of an advisor and had not helped South Vietnam against North Vietnam, the attack on the American naval vessel would not have happened.