Washington ? Richard Helms, the dapper career intelligence agent who rose through the ranks to lead the CIA for six years before President Nixon fired him for refusing to block an FBI probe into the Watergate scandal, has died. He was 89.

Considered the consummate operations officer whose advice was sought by many of his successors, Helms played a critical role in many of the CIA’s most controversial and troubling operations, from plotting the assassinations of foreign leaders such as Fidel Castro to overthrowing the Marxist government of Chilean President Salvador Allende Gossens.

Helms died Tuesday night at his Washington home, the CIA confirmed. No immediate cause of death was given, but Helms had been in poor health for some time.

The tall, lean tennis enthusiast with the detached demeanor made an effort to be part of the intelligence world after he left the field. Agents often turned to him in times of trouble, said Thomas Powers, who wrote about Helms in his authoritative 1979 book, “The Man Who Kept the Secrets.”

“During Iran-Contra, a lot of CIA people suddenly found themselves on the wrong end of an investigation. Helms would call up those people, invite them to dinner or lunch and he would more or less tell them how you live through this, and believe me, they were grateful,” Powers said.

What Helms carried away from the agency was “a lifetime of learning to understand how Washington works, what presidents are like, what you can expect at the hands of a congressional committee, and how journalists go after stories,” Powers said. “These are things that are hard-won information and that Helms had in spades.”

Career spy

After a brief stint in journalism, Helms began his spying career during World War II with the Office of Strategic Services. He was well entrenched in America’s nascent spy establishment when the OSS became the Central Intelligence Agency.

Richard Helms, left, speaks with President Nixon, in this 1973 file photo at the White House. Helms, a career spy who became director of the CIA, was fired by Nixon when he refused to block an FBI probe into the Watergate scandal. Helms died Tuesday at age 89.

Helms had a remarkable career in spying’s murky underworld, believed deeply in the CIA’s mission and was one of its biggest boosters.

“I believed in the importance to the nation of the function that the agency served. I still do without regrets, without qualms, without apology,” he told the Rockefeller Commission, which in 1975 investigated allegations of unlawful CIA activities in the United States.

Helms became deputy director of the CIA in 1965 and became the first career spy to head the agency after President Lyndon B. Johnson nominated him to the post the following year.

First for Johnson and later under President Richard Nixon, Helms headed Operation Chaos, which spied on, poked into and disrupted the private lives of U.S. citizens as the CIA improperly investigated whether the increasingly energetic and powerful anti-Vietnam War movement had links to foreign countries.

Under Nixon, the CIA’s role in domestic spying hovered on the extreme edge of the agency’s charter and at times crossed over into activities that clearly were illegal. It wasn’t long before Helms found the CIA sucked into the Watergate abyss.

The burglars who broke into the Democratic Party’s offices worked for his agency. Nixon then tried to enlist Helms’ help in blocking the FBI’s investigation. When he refused to cooperate, Nixon sent Helms packing to Tehran where he served as ambassador to Iran.

Battles on the Hill

Over the next few years, however, Helms repeatedly was called back to Washington to testify before congressional committees investigating CIA operations. By the mid-1970s it become clear that Helms had intentionally misled Senate committees, but Helms defended his testimony by maintaining that his mission was to protect intelligence secrets and that he’d not been obliged to tell the truth to Senate committees that held no CIA oversight power.

Federal prosecutors refused to accept Helms’ explanation and sought to indict him for perjury. Helms responded by saying he was prepared to play hardball, go to trial and publicly reveal matters the government wanted to remain untold. The Justice Department backed down.

In the end, Helms accepted a plea bargain, paid a $2,000 fine and received a suspended two-year prison sentence. He considered the criminal conviction a “badge of honor,” and President Ronald Reagan later presented him with the National Security Medal for “exceptionally meritorious service.”