America’s chief intelligence officers have a longstanding history of untruthiness -- testifying falsely and fearlessly.

They are caught in a dilemma -- sworn to secrecy yet sworn to tell the truth. Sometimes they get their facts wrong; that’s human error. But sometimes their untruths are conscious. Soldiers can die as a consequence.

This practice can slowly corrode a cornerstone of democracy, the rule of law.

The latest episode involves the testimony of the director of national intelligence, James Clapper, in March on the National Security Agency’s eavesdropping on Americans. The question to Clapper from the Senate Intelligence Committee was straightforward: “Does the NSA collect any type of data at all on millions or hundreds of millions of Americans?” Clapper simply answered: “No.”

Now, almost four months later, he concedes: “My response was clearly erroneous.” He corrected the record only after the metadata program was revealed by the meta-leaker Edward Snowden.

Clapper joins a grand tradition. Allen Dulles, the Cold War commander of the Central Intelligence Agency, was a champion at untruthiness.

Dulles described his vision of a small, subtle spy service to Congress in 1947. “The personnel need not be very numerous,” he said. A few hundred men would do the trick. By January 1951, Dulles commanded worldwide covert operations as deputy director of central intelligence, with thousands of paramilitary troops and a secret budget worth $3.5 billion today.

Guatemala Coup

Dulles went to a formal White House briefing for President Dwight Eisenhower on the CIA’s 1954 coup in Guatemala, in which the agency overthrew a freely elected president and installed a pliant pro-U.S. colonel named Carlos Castillo Armas. “How many men did Castillo Armas lose?” Ike asked. Only one, said the CIA’s briefer. “Incredible,” said the president.

At least 43 of Castillo Armas’s men had been killed. Dulles didn’t correct the record. This was a turning point. Cover stories required for covert action overseas were now part of the CIA’s political conduct in Washington.

“Many of us who joined the CIA did not feel bound in the actions we took as staff members to observe all the ethical rules,” said Richard Bissell, chief architect of the Bay of Pigs invasion and the development of the U-2 spy plane. In theory, only the president had the power to order a U-2 mission. But Bissell ran the program, and he was petulant about filing flight plans. He argued with the White House to risk one last spy flight over the Soviet Union, just days before a planned peace conference in Paris between Ike and the Soviet leader. On May Day 1960, as the president had feared, the U-2 was shot down in central Russia.

Dulles put out the cover story: A weather plane had been lost in Turkey. Eisenhower was stuck with it. Then Moscow revealed that it had captured the CIA pilot, alive. The peace summit was scuttled; the president was shattered. Eisenhower walked into the Oval Office on May 9 and said out loud: “I would like to resign.” In retirement, he said the greatest regret of his presidency was “the lie we told about the U-2. I didn’t realize how high a price we were going to pay for that lie.”

Richard Helms, director of central intelligence from 1966 to 1973, paid his own price. President Richard Nixon nominated him as ambassador to Iran. During the confirmation hearings on his appointment, Helms was asked, under oath, about the overthrow of President Salvador Allende of Chile. Did the CIA have anything to do with that? No, sir, Helms had answered. He eventually stood before a federal judge on a charge of a misdemeanor count of failing to tell Congress the whole truth.

Casey’s Contempt

William Casey, director of central intelligence from 1981 to 1987, was “guilty of contempt of Congress from the day he was sworn in,” said his deputy, Robert Gates, who later served as the agency’s director and as secretary of defense.

Admiral Bobby Ray Inman was the director of the NSA when President Ronald Reagan ordered him to serve as Casey’s No. 2. He resigned after 15 months because “I caught him lying to me in a number of cases.” The deceit spread downward from the director’s office; it led to the tragicomedy in which the White House and the CIA sold weapons to Iran’s Revolutionary Guard and skimmed the profit to finance counterrevolutionaries in Central America.

George Tenet, director of central intelligence from 1997 to 2004, told the Senate Intelligence Committee on Sept. 17, 2002: “Iraq provided al-Qaeda with various kinds of training -- combat, bomb-making, and chemical, biological, radiological and nuclear.” He based that statement on the confessions of a fringe player in the global jihad who had been beaten, stuffed in a 2-foot-square box for 17 hours and threatened with prolonged torture.

The prisoner had recanted after the threat of torture receded. Tenet didn’t correct the record.

On Oct. 7, 2002, expanding on the CIA’s shaky intelligence, President George W. Bush said that Iraq “possesses and produces chemical and biological weapons.” He went on to warn that “Iraq could decide on any given day to provide a biological or chemical weapon to a terrorist group or individual terrorist.”

Days before, Tenet’s deputy, John McLaughlin, had contradicted the president’s claims directly, in testimony to the Senate Intelligence Committee. On orders from the White House, Tenet issued a statement: “There is no inconsistency between our view of Saddam’s growing threat and the view as expressed by the president.”

That wasn’t true. “It was the wrong thing to do,” Tenet testified almost four years later, after more than 3,000 American deaths. It was the last thing he should have said, and he knew it.

(Tim Weiner, a former national security correspondent for the New York Times, is the author, most recently, of “Enemies: History of the FBI.”)

To contact the writer of this article: Tim Weiner at tiwein@hotmail.com.

To contact the editor responsible for this article: Katy Roberts at kroberts29@bloomberg.net.