Mac was fighting Nam after the Cuban missile crisis. Every step was with Rooskies threatening nukes and ChiComs threatening invasion.
The Chicoms were still recovering after Korea. They lost a million men along with the NORKS in the Gen. Matthew Ridgway's "meatgrinder". They supplied weapons etc. but it was a Vietnamese show.
McNamara's arrogance along with his acolytes (I know a couple)made hims over rule people who really knew what they were doing.
He and Johnson made a devilish combination, and killed a lot ofour people.