As the Senate prepares to hold hearings on Monday on domestic eavesdropping by the National Security Agency, old Washington hands see a striking similarity to a drama that unfolded three decades ago in the capital.In 1975, a Senate committee led by Senator Frank Church of Idaho revealed that the N.S.A. had intercepted the phone calls and telegrams of Americans. Then, as now, intelligence officials insisted that only international communications of people linked to dangerous activities were the targets, and that the spying was authorized under the president's constitutional powers. Then, as now, some Republicans complained that the government's most sensitive secrets were being splashed on the front pages of newspapers, while Democrats emphasized the danger to civil liberties.
Both in 1975 and today, officials defending the N.S.A. operation said it had prevented terrorist attacks. And Dick Cheney, who as vice president has overseen secret briefings for selected members of Congress on the N.S.A. program, was in the White House then, too, serving as a deputy to President Gerald R. Ford before succeeding Donald H. Rumsfeld as chief of staff.
The recent debate about the security agency "does bring back a lot of memories," said Walter F. Mondale, the former vice president, who served on the Church Committee as a Democratic senator from Minnesota. "For those of us who went through it all back then, there's disappointment and even anger that we're back where we started from."
Later, after becoming vice president under Jimmy Carter, Mr. Mondale helped usher a into law a major committee recommendation — that no eavesdropping on American soil take place without a warrant. That became the basis of the Foreign Intelligence Surveillance Act of 1978, the law that critics say is being violated by President Bush's decision to authorize eavesdropping without court warrants on people in the United States linked to Al Qaeda.
Bush administration officials deny that they have violated the 1978 statute, noting that apart from the special eavesdropping program, they are going to the FISA court for warrants more often than any previous administration.
But the officials say that going to the foreign intelligence court is impractical in some urgent situations when intercepting phone calls or e-mail messages might prevent a terrorist attack. They say the eavesdropping program was authorized by presidential order and vetted by lawyers both at the agency and at the Justice Department.
Asked at a Jan. 26 news conference about a comparison with President Richard M. Nixon's actions in the 1970's, President Bush said that past presidents had relied on "the same authority I've had" in order to "use technology to protect the American people."
He added: "There will be a legal debate about whether or not I have the authority to do this. I'm absolutely convinced I do."
Since The New York Times first disclosed the eavesdropping program in December, some who witnessed the earlier era have followed the news with an eerie feeling that events are being replayed.
"You feel like you're in an echo chamber, because the comments on both sides are so similar to 1975," said Loch K. Johnson, a historian of intelligence who served then as an aide to Mr. Church. "There are a lot of lessons from those times that are relevant today."
To read through the documents of the earlier era is to spot many themes from the current controversy: the cooperation of major telecommunications companies with the N.S.A.; the challenges of fast-changing communications technologies (then the expansion of satellite communications, now the Internet explosion); the legal rationale as laid out in detail by the attorney general (then Edward H. Levi, now Alberto R. Gonzales, who is to testify Monday before the Senate Judiciary Committee). Government documents from the 1970's eavesdropping controversy were posted over the weekend on the Web site of the National Security Archive, a research center at George Washington University.
The N.S.A. revelations of 30 years ago were unearthed simultaneously by the Church Committee, two House committees and the press, focusing on two programs code-named Minaret and Shamrock.
Minaret was a watch list kept between 1967 and 1973 of Americans whose international communications — phone calls and telegrams in and out of the country — were collected by the security agency
The names were mostly submitted to the N.S.A. by other agencies because of targets' suspected involvement in four kinds of activities: terrorism; drug trafficking; threats to the president; and civil disturbances with "possible foreign support or influence," as Lt. Gen. Lew Allen Jr., then the N.S.A. director, told the Church Committee. That program ended up targeting some Vietnam War protesters and civil rights activists.
Shamrock began in 1947, growing out of a World War II program for government censorship of international telegrams. Until the program was shut down in 1975, the three major international carriers, RCA Global, ITT World Communications and Western Union International, delivered copies of messages sent each day to the N.S.A.
Senator Church emphasized to General Allen that he did not question the value of using electronic spying to catch terrorists, drug dealers or potential assassins, only "the lack of adequate legal basis for some of this activity."
Mr. Levi, the attorney general, acknowledged that the law on such spying was "ill-defined" but said courts had upheld the president's power to order surveillance for foreign intelligence without warrants.
Two Republican senators, Barry M. Goldwater of Arizona and John G. Tower of Texas, fought unsuccessfully against open hearings on sensitive N.S.A. matters, particularly the three companies' cooperation. "I must state my firm opposition to this unilateral release of classified information," Mr. Tower said at one point.
Frederick A. O. Schwarz Jr., who served as the committee's chief counsel, recalled in an interview, "The question of how to handle N.S.A. was more divisive than anything else we did," including extensive hearings on C.I.A. and F.B.I. abuses.
But in the end, the committee reached a broad consensus on most of its findings, including on the critical recommendation of banning eavesdropping in the United States without warrants, Mr. Schwarz said.
After the trauma of public hearings and front-page headlines, intelligence officials, too, were ready for new, clear rules. Adm. Bobby R. Inman, who testified before the Church Committee as director of naval intelligence and became N.S.A. director in 1977, said he worked actively for passage the next year of the FISA law, which required approval of a special court for eavesdropping on American soil.
"I became convinced that for almost anything the country needed to do, you could get legislation to put it on a solid foundation," Admiral Inman said. "There was the comfort of going out and saying in speeches, 'We don't target U.S. citizens, and what we do is authorized by a court.' "
But not all agreed, then or now, that the president's powers over foreign intelligence should be overseen by judges. While Vice President Cheney has not explicitly criticized the FISA statute, he has often said that laws passed in reaction to Vietnam and Watergate unjustifiably weakened the presidency.
"Over the years there had been an erosion of presidential power and authority," Mr. Cheney told reporters on Dec. 20 when asked about the eavesdropping program. "The president of the United States needs to have his constitutional powers unimpaired, if you will, in terms of the conduct of national security policy. That's my personal view."
Former Senator Gary W. Hart, a Colorado Democrat who served on the Church Committee, believes views such as Mr. Cheney's have set the clock back 30 years.
"What we're experiencing now, in my judgment, is a repeat of the Nixon years," Mr. Hart said. "Then it was justified by civil unrest and the Vietnam war. Now it's terrorism and the Iraq war."
But on Friday, Senator Pat Roberts of Kansas, the current chairman of the Senate Intelligence Committee, strongly defended the eavesdropping program and dismissed any comparison to the Nixon era.
Writing to Howard Dean, the Democratic Party chairman, who had compared the current controversy to "the abuse of power during the dark days of President Nixon," Mr. Roberts declared, "Any suggestion that a program designed to track the movement, locations, plans or intentions of our enemy particularly those that have infiltrated our borders is equivalent to abusive domestic surveillance of the past is ludicrous."
He added: "When President Richard Nixon used warrantless wiretaps, they were not directed at enemies that had attacked the United States and killed thousands of Americans."