WASHINGTON — In the wake of the Sept. 11 attacks, the Bush administration determined that certain constitutional rights would not apply as the U.S. stepped up its response to terrorism, according to documents released to the public for the first time.

In nine legal opinions disclosed yesterday by the Obama administration, the Justice Department under President George W. Bush claimed exceptional search-and-seizure powers. Within two weeks of the 2001 attacks, government lawyers were discussing ways to wiretap U.S. conversations without warrants.

Also revealed by the Obama administration in court documents yesterday: The CIA destroyed nearly 100 videotapes — far more than previously known — of interrogations and other treatment of terror suspects. Congressional Democrats and other critics have charged that some of the harsh interrogation techniques amounted to torture, a contention that Bush and other officials rejected.

The Bush administration eventually abandoned many of the legal conclusions, but the documents themselves had been closely held. By releasing them, President Barack Obama continued a house-cleaning of the Bush administration's most contentious policies.

"Too often over the past decade, the fight against terrorism has been viewed as a zero-sum battle with our civil liberties," Attorney General Eric Holder said in a speech as the documents were being prepared for release. "Not only is that school of thought misguided, I fear that in actuality it does more harm than good."

The legal memos written by the Bush administration's Office of Legal Counsel show a government grappling with how to wage war on terrorism in a fast-changing world. The conclusion, reiterated in page after page of documents, was that the president had broad authority to set aside constitutional rights.

Fourth Amendment protections against unwarranted search and seizure, for instance, did not apply in the United States as long as the president was combating terrorism, the Justice Department said in an Oct. 23, 2001, memo.

"First Amendment speech and press rights may also be subordinated to the overriding need to wage war successfully," Deputy Assistant Attorney General John Yoo wrote, adding later: "The current campaign against terrorism may require even broader exercises of federal power domestically."

On Sept. 25, 2001, Yoo discussed possible changes to the laws governing wiretaps for intelligence gathering. In that memo, he said the government's interest in keeping the nation safe following the terrorist attacks might justify warrantless searches.

That memo did not specifically attempt to justify the government's warrantless-wiretapping program, but it provided part of the foundation.

Yoo, now a professor at the University of California at Berkeley School of Law, did not return messages seeking comment. Former Attorney General Alberto Gonzales, who served as White House counsel when many of the memos were written, did not respond in time for this story to a request for comment made through his attorney.

The memos reflected a belief within the Bush administration that the president had broad powers that could not be checked by Congress or the courts. That stance, in one form or another, became the foundation for many policies: holding detainees at Guantanamo Bay, eavesdropping on U.S. citizens without warrants, using tough new CIA interrogation tactics and locking U.S. citizens in military brigs without charges.

Obama has pledged to close the Guantanamo Bay prison within a year. He halted the CIA's intensive interrogation program. And last week, prosecutors moved the terrorism case against U.S. resident Ali Al-Marri, a suspected al-Qaida sleeper agent held in a military brig, to a civilian courthouse.

A criminal prosecutor is wrapping up an investigation of the destruction of the tapes of interrogations.

Yesterday's acknowledgment of the CIA’s videotape destruction, however, involved a civil lawsuit filed in New York by the American Civil Liberties Union. It was not clear what exactly was on the recordings. The government's letter cites interrogation videos, but the lawsuit against the Defense Department also seeks records related to treatment of detainees, any deaths of detainees and the CIA's sending of suspects overseas, known as "extraordinary rendition."

At the White House, Press Secretary Robert Gibbs told reporters he hadn't spoken to the president about the report, but he called the news about the videotapes "sad" and said Obama was committed to ending torture while also protecting American values.

ACLU attorney Amrit Singh said the CIA should be held in contempt of court for holding back the information for so long.