In his first public appearance as the White House counter-terrorism advisor, John O. Brennan said that President George W. Bush's policies had been an affront to American values, undermined the nation's security and fostered a "global war" mind-set that served only to "validate Al Qaeda's twisted worldview."
"Rather than looking at allies and other nations through the narrow prism of terrorism -- whether they are with us or against us -- the [Obama] administration is now engaging other countries and people across a broader range of areas," Brennan said.
The sharp language is likely to extend the war of words between the current administration and conservative critics such as former Vice President Dick Cheney, who has carried out an unusually high-profile campaign accusing Obama of abandoning methods that made the country safe.
Brennan's speech was the latest in a series of addresses by senior administration figures in recent weeks outlining the president's national security agenda.
Brennan emphasized the argument that the United States must move beyond using the CIA and the military to attack Al Qaeda and must work to expand economic and educational opportunities across the Muslim world.
"We cannot shoot ourselves out of this challenge," Brennan said. "If we fail to confront the broader political, economic and social conditions in which extremists thrive, then there will always be another recruit in the pipeline, another attack coming downstream."
Brennan presented what he described as a multi-tiered approach -- including using the U.S. military to train the security forces of allied countries, supporting democratic reforms and directing billions of dollars in aid to impoverished regions of Afghanistan and Pakistan.
Even while seeking to advance the Obama administration's agenda, Brennan often struck a defensive tone.
At one point, he decried "the inflammatory rhetoric, hyperbole and intellectual narrowness that has often characterized the debate over the president's national security policies."
Brennan had been a casualty of attacks from the left as Obama was assembling his leadership team.
Widely considered a leading candidate to run the CIA under Obama, Brennan -- who had spent most of his career in the agency -- was forced to withdraw in the face of criticism that he was too closely tied to the harsh tactics employed by the Bush administration.
Brennan complained at the time that his critics were misinformed.
On Thursday, he denounced the CIA's use of waterboarding and other interrogation measures. Such methods, he said, serve only as "a recruitment bonanza for terrorists, increase the determination of our enemies and decrease the willingness of other nations to cooperate with us."
At the White House, Brennan has been deeply involved in the work of committees that Obama established to overhaul the CIA's interrogation procedures and to close the military prison at Guantanamo Bay, Cuba.
This week, administration officials acknowledged that they were considering a plan that would set up detention and trial facilities for Guantanamo inmates in the United States, possibly in Kansas or Michigan.
Brennan declined to comment on the deliberations but indicated that the administration believed it was on target to meet its January deadline to close the Cuba facility.
The president's objective is for Guantanamo to "be shuttered -- there'd be no detainees there," Brennan said. "We are going to get there."