Washington » For two years on the presidential campaign trail, Barack Obama rallied crowds with strongly worded critiques of the Bush administration's most controversial counterterrorism programs, from hiding terrorism suspects in secret CIA jails to questioning them with methods he denounced as torture.

Now Obama must take charge of the CIA, in what is already proving to be one of the more treacherous patches of his transition to the White House.

Last week, John Brennan, a CIA veteran who was widely seen as Obama's likeliest choice to head the intelligence agency, withdrew his name from consideration after liberal critics attacked his alleged role in the agency's detention and interrogation program. Brennan protested that he had been a "strong opponent" within the agency of harsh interrogation tactics, yet Obama evidently decided that nominating Brennan was not worth a battle with some of his most ardent supporters on the left.

Obama's search for someone else and his future relationship with the agency are complicated by the tension between his apparent desire to make a clean break with Bush administration policies he has condemned and concern about alienating an agency with a central role in the campaign against al-Qaida.

Mark Lowenthal, an intelligence veteran who left a senior post at the CIA in 2005, said Obama's decision to exclude Brennan from contention for the top job had sent a message that "if you worked in the CIA during the war on terror, you are now tainted," and had created anxiety in the ranks of the agency's clandestine service.

One of the first issues Obama must grapple with is the future of CIA detention: Will the agency continue to hold prisoners secretly, question them using more aggressive methods than allowed for military interrogators, and transfer terrorism suspects to countries with a history of using torture?

During the presidential campaign, a constant theme for Obama was the need to restore "American values" to the fight against terrorism. He pledged to banish secret CIA interrogation rules and require all American interrogators to follow military guidelines, set out in the Army Field Manual on interrogation.

In a speech last year, Obama cast the matter as a practical issue, as well as a moral one. "We cannot win a war unless we maintain the high ground and keep the people on our side," he said. "But because the administration decided to take the low road, our troops have more enemies."

On Wednesday, a dozen retired generals and admirals are to meet with senior Obama advisers to urge him to stand firm against any deviation from the military's noncoercive interrogation rules.

But even some senior Democratic lawmakers who are vehement critics of the Bush administration's interrogation policies seemed reluctant in recent interviews to commit the new administration to following the Army Field Manual in all cases.

Sen. Dianne Feinstein, D-Calif., who will take over as chairman of the Senate Intelligence Committee in January, led the fight this year to force the CIA to follow military interrogation rules. Her bill was passed by Congress but vetoed by President George W. Bush.

But in an interview on Tuesday, Feinstein indicated that extreme cases might call for flexibility. "I think that you have to use the noncoercive standard to the greatest extent possible," she said, raising the possibility that an imminent terrorist threat might require special measures.

Afterward, however, Feinstein issued a statement saying: "The law must reflect a single clear standard across the government, and right now, the best choice appears to be the Army Field Manual. I recognize that there are other views, and I am willing to work with the new administration to consider them."

Sen. Ron Wyden of Oregon, another top Democrat on the Intelligence Committee, said he would consult with the CIA and approve interrogation techniques that went beyond the Army Field Manual as long as they were "legal, humane and noncoercive." But Wyden declined to say whether CIA techniques ought to be made public.

CIA officials have long argued that publishing a list of interrogation techniques only allows al-Qaida to train its operatives to resist them. But they say the secrecy has led to exaggeration and myth about the agency's detention program.

During the presidential campaign, Obama's aides said he would consider allowing the CIA to continue holding prisoners in overseas jails, but would insist that inspectors from the International Committee of the Red Cross be allowed to visit them. They also said he would end the practice of "rendering" terrorism suspects to countries that have used torture.

One of the retired generals meeting with the Obama team on Wednesday, Paul Eaton, who oversaw the training of Iraqi forces for the Army in 2003 and 2004, said in an interview Tuesday that it was crucial for leaders to send the right message on the treatment of prisoners.

Eaton pointed out that Vice President Dick Cheney once dismissed waterboarding, the near-drowning procedure considered by many legal authorities to be torture, as a "dunk in the water" and said such statements influenced rank-and-file soldiers to believe that brutality was not really prohibited.

"This administration has set a tone problem for the military," Eaton said. "We've had eight years of undermining good order and discipline."

It is widely expected that Obama will replace Michael Hayden, the CIA director. Among those mentioned as possible candidates for the job are Stephen Kappes, a CIA veteran who is the deputy director; Tim Roemer, a former congressman from Indiana who was a member of the Sept. 11 commission; Sen. Chuck Hagel, R-Neb., who is retiring from the Senate in January; and Jack Devine, a former head of the agency's clandestine service who left the CIA before the Sept. 11 attacks.

The flap over Brennan, who served as a chief of staff to George Tenet when he ran the CIA, was the biggest glitch so far in what has been an otherwise smooth transition for Obama. Some CIA veterans suggest that the president-elect may have difficulty finding a candidate who can be embraced by both veteran officials at the agency and the left flank of the Democratic Party.

A.B. Krongard, the CIA's third-ranking official under Tenet when the detention and interrogation program was created, called Brennan a "casualty of war" and said he believed CIA tactics were being second-guessed for political purposes. The demise of Brennan's candidacy, Krongard said, "is a huge loss to the country."

But Krongard said he believed that ultimately, under a new director and a new set of policies, the agency would find common ground with Obama.

"The CIA's no different than any other place," he said. "Probably 25 percent of the people there really like him, 25 percent don't like him, and 50 percent are open-minded."