As to Walter, well, I hate what he did to us in Nam, but LBJ spent his entire presidency proving that bad enough leadership could screw anything up. We lost Nam, and Walter didn't help our cause, but LBJ was trying to create a Korea situation. He didn't want to win, he wanted the US to control half the country. That's the reason we dug five deep water ports in Nam. We wanted a place for our carriers to dock.
That's the reason the Chinese fought so fiercely, and we were fighting the Chinese there, just as we did in Korea. Control of Viet Nam would have given us control of just about the entire Pacific Rim coastline.