The White House said Wednesday that the widely condemned interrogation technique known as waterboarding is legal and that President Bush could authorize the CIA to resume using the simulated-drowning method under extraordinary circumstances.

The surprise assertion from the Bush administration reopened a debate that many in Washington had considered closed. Two laws passed by Congress in recent years -- as well as a Supreme Court ruling on the treatment of detainees -- were widely interpreted to have banned the CIA’s use of the extreme interrogation method.

But in remarks that were greeted with disbelief by some members of Congress and human rights groups, White House spokesman Tony Fratto said that waterboarding was a legal technique that could be employed again “under certain circumstances.”

Fratto said the nation’s top intelligence officials “didn’t rule anything out” during congressional testimony Tuesday on CIA interrogation methods, and he indicated that Bush might consider reauthorizing waterboarding or other harsh techniques in extreme cases, such as when there is “belief that an attack might be imminent.”

For years, White House officials denied that the U.S. had engaged in torture but always stopped short of confirming whether waterboarding had been used. The administration’s latest stance -- described by Fratto during the daily White House briefing -- was denounced Wednesday by key lawmakers. “This is a black mark on the United States,” said Sen. Dianne Feinstein (D-Calif.), a member of the Senate Intelligence Committee. “The White House is trying to give themselves as much of an open field here as possible. It says to others that we are prepared to use the same kinds of tactics used by the most repressive regimes and the most heinous regimes.”

The White House comments came one day after CIA Director Michael V. Hayden testified publicly for the first time that the agency had used waterboarding on Al Qaeda suspects in 2002 and 2003. He also identified three prisoners, including self-proclaimed Sept. 11 mastermind Khalid Sheikh Mohammed, who he said were the only detainees subjected to the method.

Waterboarding refers to a practice that involves strapping down a prisoner, placing a cloth over his face and dousing him with water to simulate the sensation of drowning. The technique has been traced to the Spanish Inquisition and has been the subject of war-crimes trials dating back a century.

The White House position on the issue is in some ways consistent with its long-standing efforts to expand executive power and resist attempts by Congress to rein in the president’s authority.

Still, the decision to reignite the debate over waterboarding struck many in Washington as peculiar. The White House had previously argued that any discussion of CIA interrogation methods would only aid the enemy. Further, the CIA halted its use of waterboarding nearly five years ago. Calling renewed attention to the issue risks drawing fresh criticism from other countries at a time when the United States is seeking to shore up its image abroad.

The issue also has been divisive politically for Republicans. Sen. John McCain of Arizona, now the front-runner for the GOP presidential nomination, has led efforts to outlaw waterboarding and other harsh interrogation methods previously employed by the CIA.

In a recent GOP presidential debate, McCain said it was inconceivable that “anyone could believe that [waterboarding is] not torture. It’s in violation of the Geneva Convention. It’s in violation of existing law.”

The leading Democratic contenders for the White House, Sens. Hillary Rodham Clinton of New York and Barack Obama of Illinois, have taken similar positions.

Largely because the presidential candidates are consistent on the issue, many experts consider it unlikely that the CIA would resume using the method, because agency operatives would fear prosecution under a future administration.

“On Jan. 21, 2009, there’s almost certainly going to be a new president who understands that waterboarding is not only wrong but a very serious crime,” said Tom Malinowski, the Washington advocacy director of Human Rights Watch.

However, Atty. Gen. Michael B. Mukasey, challenged by senators to rule on the legality of waterboarding, declined last month to say it was illegal, even though he said he would consider it torture if he were subjected to it.

Congress has passed two laws -- the Detainee Treatment Act in 2005 and the Military Commissions Act in 2006 -- that ban the use of harsh interrogation methods and require all U.S. agencies to comply with the Constitution and the Geneva Conventions in their treatment of detainees.

In addition, the Pentagon published a new Army field manual in 2006 that limits interrogation techniques and bans harsh methods, including waterboarding, hoods and mock executions. And the Supreme Court in 2006 struck down the Bush administration’s system for holding and prosecuting detainees, saying it failed to provide protections under the Geneva Conventions.

Sen. Lindsey Graham (R-S.C.), one of the Republican sponsors of the 2006 Military Commissions Act, said in a telephone interview Wednesday that at the time the bill was passed he was assured by the Bush administration that the law would specifically prohibit waterboarding.

But Fratto appeared to contradict that, saying that the Justice Department had reviewed waterboarding and “made a determination that its use under specific circumstances and with safeguards was lawful.” The CIA is not currently authorized to use waterboarding, he said, adding that “we’re not going to be able to speculate on what might be the case in the future.”

Fratto outlined a series of steps that would be required before waterboarding or other coercive methods would be approved. He said that the CIA director would have to make a proposal to the attorney general, who would have to review the interrogation plan to determine whether it would be legal and effective.

“At that point, the proposal would go to the president; the president would listen to the determinations of his advisors and make a decision,” Fratto said.

Fratto’s comments echoed statements by Hayden as well as Director of National Intelligence J. Michael McConnell in testimony before the Senate Intelligence Committee on Tuesday. In referring to special circumstances under which more aggressive methods might be authorized, administration officials may be making the case for a kind of sliding scale for detainee treatment.

Malinowski said the administration may be seeking to define a loophole in international laws banning prisoner treatment that would “shock the conscience.” That standard, the administration might argue, could shift dramatically if there was reason to fear the country was in danger of imminent attack.

But even so, McCain and Graham recently signed a letter to Mukasey saying that it was “beyond dispute that waterboarding ‘shocks the conscience.’ ” And other experts said it would be more difficult to make such interpretations of the Geneva Conventions and other standards.

Feinstein has sponsored a provision in a pending intelligence bill that would require the CIA to abide by the stricter interrogation rules in the Army field manual. The measure has already passed the House and is expected to be considered by the Senate in the coming weeks. Bush has threatened to veto the bill.

During Tuesday’s testimony, Hayden said that depriving the CIA of enhanced techniques would place America in greater danger. After the hearing, a senior U.S. intelligence official argued that waterboarding should not be considered torture because the U.S. military has subjected its own personnel to the method to prepare them for the possibility of being captured.

“Tens of thousands of American Air Force and naval airmen were waterboarded as part of their survival training,” said the official, who spoke on condition of anonymity. “We don’t maim as part of our training. We don’t mutilate. We don’t sodomize. Those are things that are always bad. . . . Intellectually, there has got to be a difference between [waterboarding] and the others; otherwise we wouldn’t have done it in training.”

greg.miller@latimes.com