Eltab
Lord of the Hidden Layer
President Johnson trapped himself inside a box of Can'ts that crippled his policy and strategy options. Any proposal that would break the ongoing stalemate got the reaction "We can't do that".Vietnam is a weird beast. The US decisively won every single battle and still lost the war.
And, even in Vietnam, losses were extremely one sided.
Subsequent Presidents have learned from LBJ's experience and mistakes.