From today's NY Times, John McCain: By the Book

What are the best books you’ve read about Vietnam?

“Hell in a Very Small Place” and “Street Without Joy,” by Bernard Fall, and “A Bright Shining Lie,” by Neil Sheehan. Fall’s two classics on the French Indochina War warned us about the mistakes we should have avoided making in Vietnam. Sheehan’s book examining America’s involvement in Vietnam through the experiences of John Paul Vann shows how we went about making them anyway.

Rob's comment:

I suspect that McCain read Fall's books after he returned in 1973 from the prison camp in Vietnam. Sheehan's book was published in 1988.

Donald Trump, a chickenhawk during the Vietnam war, belittled McCain's experience as a prisoner of war, but McCain did display heroism as a prisoner:

McCain spent six weeks in the hospital, where he received marginal care. He had lost 50 pounds (23 kg), was in a chest cast, and his gray hair had turned as white as snow. McCain was sent to a different camp on the outskirts of Hanoi. In December 1967, McCain was placed in a cell with two other Americans who did not expect him to live more than a week. In March 1968, McCain was placed into solitary confinement, where he would remain for two years.

In mid-1968, his father John S. McCain Jr. was named commander of all U.S. forces in the Vietnam theater, and the North Vietnamese offered McCain early release because they wanted to appear merciful for propaganda purposes, and also to show other POWs that elite prisoners were willing to be treated preferentially. 

McCain refused repatriation unless every man taken in before him was also released. Such early release was prohibited by the POWs' interpretation of the military Code of Conduct which states in Article III: “I will accept neither parole nor special favors from the enemy.” 

To prevent the enemy from using prisoners for propaganda, officers were to agree to be released in the order in which they were captured.

Beginning in August 1968, McCain was subjected to a program of severe torture. He was bound and beaten every two hours; this punishment occurred at the same time that he was suffering from dysentery. Further injuries led McCain to attempt suicide, which was stopped by guards. 

Eventually, McCain made an anti-U.S. propaganda "confession." He has always felt that his statement was dishonorable, but as he later wrote, "I had learned what we all learned over there: every man has his breaking point. I had reached mine." 

Many U.S. POWs were tortured and maltreated in order to extract "confessions" and propaganda statements; virtually all of them eventually yielded something to their captors. 

McCain received two to three beatings weekly because of his continued refusal to sign additional statements.