The problem is that the lying, weasels DID know what was going on. McNamara confessed to this finally in a self serving book he wrote several years ago.
LBJ/McNamara/Clifford and all the rest deliberately prevented us from winning in order to have enough money for their (failed) Great Society Program. By the way that is where your Social Security money went too. Johnson and the DemocRATS dumped the Social Security trust fund into the "general revenues" of the Budget.Spent every damn dime of it too.
I wouldn't buy his book but did search through it at a bookstore when it came out. The only thing I was interested in was what he had to say about why we didn't launch ground assaults, by land or sea, into North Vietnam in order to force them to leave troops behind to protect their territory. The only thing I found was a statement to the effect that that tactic was never a serious option. Of course without using that option we were fighting the war on their terms. Johnson and McNamera, limiting and micro-managing the war, what a team. Notice the MSM never pushed the invasion option either.