Link to an article by investigative historian Gareth Porter:
“Robert S. McNamara and the Real Tonkin Gulf Deception: Pushing LBJ Into War”
It is interesting to consider Porter’s perspectives on this in light of the late sociologist Pierre Bourdieu’s theory of the “bureaucratic field”. That is, Porter does not view the “state” as a monolithic entity, but a field established by and through its agents (and groups of agents) struggling amongst each other for authority.