The great paradox of the American intelligence community is that the qualities of an effective covert agent often slam up against the morality and openness central to the American character — yet are essential to protecting the nation whose character is so defined.

That is the critical tension at the core of Carl Colby’s documentary “The Man Nobody Knew: In Search of My Father — CIA Spymaster William Colby.”

William Colby, the filmmaker’s father, held the top post at the CIA during the mid-1970s. He made his name as a covert operative during World War II and, later, as the architect of the Phoenix Program, a counterinsurgency effort against the Viet Cong during the Vietnam War. 

“He worked very closely with the resistance in France and particularly Norway,” Carl Colby said. “And there was a reprisal in a village where him and his resistance buddies had killed some Germans and [the Germans] took out a whole village.

“I mean, that happens in front of you, and it’s your fault, you’re blamed,” he continued. “You carry a pretty heavy heart.” 

William Colby is something of a Rebecca de Winter-type character in the film, the magnetic deceased wife in Daphne du Maurier’s novel of the same name. Like Rebecca, how William Colby is perceived may say more about the people behind the film than it said about the man himself. 

By the film’s end, however, one thing is clear: William Colby did indeed carry a heavy heart, which he paid for dearly in his public and private life. 

According to Carl Colby, his father’s opposition to tyranny went beyond anti-communism. 

“What he really was was anti-authoritarian and anti-totalitarian,” he said. “He was a warrior.”

He remembers how he used to idolize his father as a boy. 

“I’m an altar boy. I adore him. I think he’s great. He’s a war hero. I always knew that about him,” he said. “I am maybe 11 years old, and he’s the coolest guy I ever met. … And then I found out he’s CIA, and that’s even cooler.” 

That unquestioning adoration evolved, however, as the Colby children grew up and as their father became more and more involved in Vietnam.

“We questioned it,” Carl Colby remembered. The children started to ask: “Why are we involved in the war? What are we doing over there?” 

Carl Colby remembers his friends calling his father a murderer because of his activities in Vietnam. They compared him to SS Reichsführer Heinrich Himmler. 

He remembers asking his father, “Are you a criminal?”

Paradoxically, because he told Congressional investigating committees the truth, “[William Colby] was, in the end, a moral man,” said Jeff Stein, a former Washington Post and Congressional Quarterly columnist and an army intelligence officer in Vietnam.

The film suggests Colby struggled over whether the ends of the American mission in Vietnam justified the means and, later, over how much information to provide to the American public. 

At one point, William Colby told his son that he fought the war the best way he knew how. He could have added that he did it at no small price to himself, his family and his country.

“The American character,” Carl Colby said, “is one of openness, creativity, independence, sharing, expressing yourself. And this job of espionage calls on all the dark arts. It all seems un-American.”

“You … need connections into the underworld,” he continued. “To the real netherworld, the bad guys, and they’re not Boy Scouts.

“So how does that jibe with the American character?” he asked rhetorically. “It’s very hard.”

In William Colby’s world, Stein said, the objective of U.S. counterinsurgency in Vietnam was “to kill communists, not capture and hold territory,” and the Phoenix Program was “the knife edge” of that. 

Stein remembers a famous poster in a Phoenix Program office that summed up the intelligence culture: “When you got ’em by the balls, their hearts and minds will follow.”

“Colby felt this was the essence of counterinsurgency,” Stein said. “That’s what we’re doing [today] in Afghanistan … killing the underground Taliban leaders.”

According to Stein, William Colby resented that Phoenix was called “an assassination program, but that’s what it amounted to.” 

The Phoenix officers were meant to sweep into villages and round up the insurgency and “flip them” for the Americans and the South Vietnamese, but some officers did more killing than they did flipping. 

Beyond counterinsurgency, Stein explained the paradox of the covert operative this way: “[Y]ou are doing something illegal. It is subversion of foreign governments.” At the same time, the agents must strive to maintain their personal morality or personal ethics. “That’s the trick.”

In the film, “Carl tries to show that his father tried to live an ethical and moral life,” Stein said. “That’s the real riddle of him.”

The emotional core of the documentary, however, is the story of a family’s personal sacrifice in service to their country. 

William Colby and his wife, Barbara, who is in the film, were practicing Roman Catholics and raised their children in the church. 

“She’s tough,” Carl Colby said of his mother. “She comes across as very charming and beguiling [in the film], but she’s a very soulful person.” 

Barbara Colby was the standard-bearer for the family, and she serves as the film’s emotional center. She set the moral bar for five children — and her husband — high.

“She was the matriarch,” Carl Colby said. “I think, maybe, we bonded even more because of my father being away — though he was the untitled, unquestioned head of the family.”

The Colby family suffered much collateral damage that can be traced, in some measure, back to William Colby’s service: the death of a beloved daughter and sister, the end of the Colby marriage and William Colby’s mysterious death in 1996.

As William Colby served his country, his family served him, his son explained.

“I’ve never said it that way, but it’s really the truth,” Carl Colby said. “He served the country and we considered his mission unquestionably honorable, so we served him.

“Very simple.”