That war. like all wars, damaged our national psyche and created scars that still haunt us. To those too young to remember or didn't serve then it was less than 20 years after WW2, and there were still a lot of WW2 vets in and out of service and in your neighborhood. It was still uncouth to even question the military and even more we still believed the media. It was a bad war for all the wrong reasons, and people began to realize it. To rationalize killing people you first demonize and trivialize them, and that's what we did to the Vietnamese. We turned into the monsters that we claimed to be fighting, and once it started we were led by people that were incapable of telling the truth much less admit they were wrong. LBJ ended up a psychotic mess on his ranch because of all the evil he had done in his life, and Robert McMamara regretted his part, among with Kissinger, who continued chasing his own demons. I am not sure that this failure will not be repeated.
How Robert McNamara Came to Regret the War He Escalated.