In nearly half a century of newspapering I have often wished I could have written a happier ending to many of the sad tales I have been told. If only the story could have turned out a little differently, I have thought. This is one story that did.

In January I wrote of an incident during the Vietnam War, told by a CIA officer named Frank Snepp, whom I knew during those last, desperate days of the old Saigon before the fall 30 years ago.

I wrote of a windowless, snow white cell in which the CIA kept for years a north Vietnamese spy named Nguyen Van Tai. Not only was Tai kept in complete isolation except for his CIA interrogators, he was kept always cold in frigid air conditioning. This was done because the CIA knew that Tai, like many Vietnamese, had a horror of being cold.

Frank Snepp was one of his interrogators, and he found Tai a tough nut to crack. In his book, "Decent Interval," Snepp wrote that the only time he ever saw a fracture in Tai's implacable facade was when Snepp mentioned Tai's family. "I cannot think about my wife and children," Tai told Snepp. "The only way I can survive this is by putting all such hope aside. Then there are no illusions or disappointments."

As the North Vietnamese were gathering for their final assault in 1975, a senior CIA official suggested that it would be useful if Tai disappeared. And, quoting from Snepp's book, I wrote that Tai was taken from his cell, put into a helicopter, and thrown out at 10,000 feet over the South China Sea.

After the war, Snepp left the CIA, but, unable to get Tai out of his mind, he traveled to Paris specifically to pass the word through the Vietnamese mission that Tai had comported himself honorably and died bravely.

But that is not how the story ends. I am grateful to the BBC's Carol Hills, who informed me that Tai, unbeknownst to Snepp, managed to talk his South Vietnamese captors into releasing him once the last of the CIA had fled Saigon 30 years ago. Tai lives and wrote his own account of his interrogation.

Hills directed me to www.cia.gov/csi/studies.html, a CIA Web site, on which I learned that the treatment of Tai at the hands of the South Vietnamese, before CIA took over, was worse than I had known. The Web site says that "they administered electric shock, beat him with clubs, poured water down his nose while his mouth was gagged, applied 'Chinese water torture,' dripping water slowly, drop by drop, on teh bridge of his nose..., and kept (him) without food or water" while he was hanging by his arms from the rafters.

Frank Snepp did not find out that Tai survived until years later. He says today that "for me, the interrogation of Tai brought into full focus the moral ambiguity of the war. There is no question that Tai would have shot me down on the street if he'd been given a chance at the time. And I would surely have returned the favor. But face to face across the interrogation desk, the 'despicable' persona of 'our enemy' altered to reveal a deeply committed warrior enlisted in a cause he deeply felt. I could not but admire his strength, if not his ruthlessness, and wonder if his commitment might not have chastened other Americans so convinced of the righteousness of our own cause.

"Personally, the circumstances of the (CIA's) interrogation, veering so close as they did to psychological torture, eroded my own sense of certitude about my role in Vietnam," Snepp told me. "True, I always console myself that I treated Tai as well as I could. But confining Tai in that snow white room also made me realize how the war was compromising my own values. It was a catalyst to the disillusionment that would ultimately carry me out of the agency," but "I am greatly relieved that Tai was not part of the ghastly body count of that war."

The CIA Web site's account of Nguyen Van Tai affair concludes that "we as Americans must not let methods betray our goals. War is a nasty business. There is nothing wrong with a little psychological intimidation. There are limits, however, beyond which we cannot and should not go if we are to continue to call ourselves Americans."

Yet there are those high up in the current administrations who have allowed, even encouraged, the accepted limits beyond which we cannot go to slide, and the results from Guantanamo, from Afghanistan and from Abu Ghraib are more chilling than the frigid air of the white room.