The assessment of the war's impact on terrorism came in a National Intelligence Estimate that represents a consensus view of the 16 disparate spy services inside government, CBS News learned Sunday.
CBS News senior White House correspondent Bill Plante reports that the intelligence report contained some broad conclusions:
The details of the Intelligence Estimate were first published in Sunday's New York Times and Washington Post.
Three leading Republicans — Senate Majority Leader Bill Frist of Tennessee, Sen. John McCain of Arizona and Sen. Mitch McConnell of Kentucky — defended the war in Iraq and said it is vital that U.S. troops stay in the fight.
On CBS's Face The Nation, Sen. John McCain, R-Ariz. spoke cautiously of the report, saying that while he knew nothing about it, "it's obvious that the difficulties we've experienced in Iraq have certainly emboldened (terrorists) — lack of success always does that."
McCain, a likely candidate for president in 2008, agress with President Bush that the United States needs to stay and prevail in Iraq. "If we fail, then our problems will be much more complicated," he said.
Sen. Bill Frist, R-Tenn. said he had not seen the classified report, which was completed in April, but said Americans understand the United States must continue to fight terrorists in Iraq and elsewhere.
"Either we are going to be fighting this battle, this war overseas, or it's going to be right here in this country," Frist said on ABC's "This Week," echoing an argument that President Bush frequently makes.
"Attacks here at home stopped when we started fighting al Qaeda where they live, rather than responding after they hit," McConnell said in a statement.
Democrats seized on an intelligence assessment that said the Iraq war has increased the terrorist threat, saying it was further evidence that Americans should choose new leadership in the November midterm elections.
Sen. Ted Kennedy, D-Mass., said in a statement that the assessment "should put the final nail in the coffin for President Bush's phony argument about the Iraq war."
"How many more independent reports, how many more deaths, how much deeper into civil war will Iraq need to fall for the White House to wake up and change its strategy in Iraq?"
"Unfortunately this report is just confirmation that the Bush administration's stay-the-course approach to the Iraq war has not just made the war more difficult and more deadly for our troops, but has also made the war on terror more dangerous for every American," said Rep. Rahm Emanuel, head of the Democratic effort to take control of the House of Representatives in the upcoming national election.
"It's time for a new direction in this country," Emanuel, an Illinois Democrat, said in the statement.
"Press reports say our nation's intelligence services have confirmed that President Bush's repeated missteps in Iraq and his stubborn refusal to change course have made America less safe," said Senate Democratic Leader Harry Reid. "No election-year White House PR campaign can hide this truth."
A White House spokesman, Blair Jones, said "We don't comment on classified documents" and that the published accounts' "characterization of the NIE is not representative of the complete document."
The White House issued a written rebuttal that argued administration officials have been making some of the same arguments as in the intelligence estimate. A White House strategy booklet released this month described the terrorists as more dispersed and less centralized and still a threat to the United States.
Bush himself said on Sept. 5 that the "terrorist danger remains" and the broader terrorist movement is becoming more spread out and self-directed. He also quoted Osama bin Laden describing Iraq as the central battlefield in the fight against terrorism.
The president has said the United States is safer since the Sept. 11 attacks and that fighting the terrorists in Iraq keeps them from attacking America.
In other developments:
They see no sign of a direct al Qaeda hand in a flurry of recent attacks, such as the assault on the U.S. Embassy in Damascus, Syria or the fatal shooting of a British tourist in Jordan. And a recent French intelligence report that bin Laden may have died last month of typhoid fever merely highlights the uncertainty the West now has about any role he plays in the terror network.
All that means those frightening videos may have been just that —designed to frighten the West and inspire followers — with little real punch behind them.
Bin Laden and his top deputy, Ayman al-Zawahiri, are now "less like generals and more like talking heads, disseminating their violent ideology via satellite television in hopes of inspiring others to do their bidding," says Eben Kaplan of the Council on Foreign Relations think tank in New York.
Not everyone agrees with that controversial idea. There also are ominous signs in Afghanistan that al Qaeda is trying to make an operational comeback as attacks, especially suicide missions, against U.S. and coalition forces increase.
Some experts also fear the absence of a major, Sept. 11-style attack simply means that al Qaeda is taking its time to plan a next spectacular strike.
Yet, five years after the attacks on the World Trade Center, many analysts believe the day-to-day threat from al Qaeda itself has dropped.
Paradoxically, however, the threat from Islamic extremist terrorists overall may have grown — and become broader, more diverse and more complex, and thus harder to combat.
"The absence of a formal, single organizational structure has contributed to making the fight against this brand of terrorism more elusive and difficult," the British think-tank Chatham House said in a report this month as the videos were airing.
After the U.S. and its allies ousted the Taliban in 2001, al Qaeda apparently transformed itself into an ideological movement of self-sustaining cells that operate with little or no central direction, many analysts and intelligence officials believe. That makes them difficult to track — until they strike or make a mistake that leads the authorities to them.