Updated

The most significant threat facing the United States comes from a loosened Al Qaeda and splintered extremist organizations intent on attacking U.S. interests, CIA Director George Tenet (search) said Tuesday.

"A spectacular attack on the U.S. homeland remains the brass ring many strive for with or without Al Qaeda (search) leadership," Tenet testified before the Senate Armed Services Committee (search).

Tenet, appearing before the panel to present his annual worldwide threat assessment, also came under attack from Democrats for the administration's handling of intelligence leading up to the Iraq war.

In the war on terrorism, Usama bin Laden's (search) terror network has been "eroded" and key members of the group have been nabbed in Saudi Arabia, Pakistan and Yemen, including Khalid Sheikh Muhammad and Hambali, Tenet said. What remains today is a looser, decentralized group of terrorists.

"We are creating large and growing gaps in the Al Qaeda hierarchy ... disrupting plots that otherwise would have killed Americans," Tenet said, adding that the group's finances are "being squeezed."

"Nevertheless, Al Qaeda remains the greatest threat to our homeland and our overseas presence," added Vice Adm. Lowell Jacoby, director of the Defense Intelligence Agency (search), saying threats to civilian aircraft remain a "specific concern."

But still, officials in Southeast Asia, the Middle East and other areas have discovered "chilling" plots, such as the recruiting of airline pilots who can evade new security measures - "even catastrophic attacks like the 11th of September remain in Al Qaeda's reach," Tenet said.

Coalition countries such as Jordan, Morocco, Pakistan, Oman and Egypt have been helping round up Al Qaeda and other extremist suspects, the CIA director said. But there is a "steady spread" of the bin Laden effect, particularly within the Sunni extremist community.

"Al Qaeda is not the only threat," Tenet said. "The steady spread of UBL's [interest in attacking the United States] ensures that serious threat will remain through the capture with or without Al Qaeda ... dozens of extremist Sunni groups exist," including the Libyan Islamic fighting group and Islamic group of Uzbekistan.

"These groups are redefining the threat we face," Tenet said.

Foreign jihadists from groups such as these continue to be problematic for progress in Iraq, as well, Tenet said.

Intelligence has given U.S. officials and coalition forces a "good understanding" of the insurgency at the local level, Tenet said, but jihadists are purposefully decentralizing to avoid capture. And they're getting the help from the likes of foreign terrorists like Ansar al-Islam, who are able to hide out in the "jihadists safehaven" that is the Sunni heartland.

"The situation ... indicates we have damaged yet not yet defeated the insurgents," Tenet said. "Their goal is clear ... to threaten coalition forces and put a halt to the long-term process of building democratic institutions and governance in Iraq."

The Credibility Question

The Bush administration has come under steady fire by Democrats and others for what they call faulty intelligence leading up to the Iraq war, which indicated that Saddam Hussein had weapons of mass destruction that posed a significant threat to U.S. interests.

Pressed by Senate Democrats, Tenet said he has told policy-makers when they were mischaracterizing intelligence. He said, for example, that he had called Vice President Dick Cheney about one discrepancy and planned to call him again to say Cheney had referred to a discredited document in a newspaper interview.

Tenet also made clear that he believes policy-makers are entitled to flexibility in how they interpret and describe intelligence.

"At the end of the day, they make policy judgments and they talk about things differently," Tenet told the Senate Armed Services Committee.

Sen. Carl Levin, D-Mich., ranking member of the committee, said confidence in American intelligence agencies needs to be restored after the U.S. intelligence community's "credibility has been badly damaged by the intelligence fiasco" relative to that weapons investigation so far — which has not turned up such weapons but has discovered evidence that Saddam was pursuing a biological weapons program.

"The intelligence community was so wrong about Iraq's weapons of mass destruction that it understandably raises questions about what they say about other looming issues," said the Michigander. "Initiating a war on the basis of faulty or exaggerated intelligence is a very serious matter."

Sen. Ted Kennedy, D-Mass., launched a fiery round of questions at Tenet, asking him if he ever stood up to the White House to say its estimation that the threat in Iraq was like a "mushroom cloud" or a "unique and urgent" threat to the United States was overstated.

"When do you say no?" Kennedy asked.

"I'm not going to sit here today and tell you what my interaction was, what I did or didn't do," Tenet responded, noting that he's served the Clinton and Bush administrations in the same manner. "You have to have confidence that when I believed somebody was misconstruing intelligence, I say something about it.

"We believed he was continuing his efforts to deceive us and build programs that might constantly surprise us and threaten our interests," he added.

Republicans were quick to point out the Democratic attacks are well-timed.

"No doubt we're in an election year — a presidential election," said Sen. Wayne Allard, R-Colo., after Kennedy's questioning, noting that despite the criticisms, Tenet has been a "true professional."

Committee Chairman John Warner, R-Va., pointed out that 45 of Iraq's 55 most-wanted have been captured, including Saddam. Key Al Qaeda operatives have been nabbed as well, and the U.S. intelligence community has been key to those events, he said.

"In my view, the world is more secure now," Warner said, noting that he's not suggesting intelligence failures be ignored, but that "we have the best intelligence community in the world."

Sen. Pat Roberts, R-Kan., chairman of the Senate Select Committee on Intelligence, noted that some are calling for an independent investigation of the pre-Iraq war intelligence, despite the fact that the intelligence community and others working to protect the United States are being called away from work to be scrutinized by a myriad of independent panels, House and Senate investigations, and others, to determine the "lord of the links."

"Are we splitting the shingle here?" Roberts asked. "That's a Dodge City term where you hit the shingle 17 times and you split it ... is there anybody left down at Langley [CIA headquarters] doing their job?"

"We're working through it. Obviously it takes us away from our work but it's an important issue and we'll work through it as best we can," Tenet responded.

"I think the only thing lacking is an independent investigation to investigate the independent commissions," Roberts retorted.

Fox News' Julie Asher contributed to this report.