Concern over the quality of the information on Iraq raises the question: If the intelligence community was wrong about Saddam Hussein's intentions, then why should we assume it's right about recent warnings of possible al-Qaida terror attacks in the United States this summer?
Intelligence officials say there are several reasons to believe that al-Qaida fervently hopes to attack the U.S. during the coming political season.
Reason one, they say, is that this information comes from a number of different sources, collected in different ways. Those sources include human intelligence and friendly governments. "We can assume that it's not just one particular stream they're relying on. And if that's the case, then no one here has a political agenda," says terrorism expert Roger Cressey.
Reason two is this intelligence is corroborated — with new sources backing up older information. One important source, NBC News has learned, is Hasan Ghul, a top al-Qaida operative who was picked up by U.S. soldiers in Iraq in January.
Reason three: Recent patterns of attempted terror attacks overseas, where apparent sleeper cells were in place, with the materials they needed. Following that model, officials say they fear there could be sleeper cells in the United States too.
Members of Congress, briefed by FBI Director Robert Mueller and others, say they find it all credible. "I take it seriously. I agree there are huge problems at the CIA and across our intelligence community, but they are also capable of producing good intelligence," says Rep. Jane Harman, D-Calif.
Based on their analysis, intelligence officials say they believe the threat of an attack increases, the closer we get to the November elections.