Imagine that Saddam Hussein has been offering terrorist training and other lethal support to Osama bin Laden's al Qaeda for years. You can't imagine that? Sign up over there. You can be a Middle East analyst for the Central Intelligence Agency.

Or at least you could have been until recently. As President Bush's determination to overthrow the Iraqi dictator has become evident to all, a cultural change has come over the world's most expensive intelligence agency: Some analysts out at Langley are now willing to evaluate incriminating evidence against the Iraqis and call it just that.

That development has triggered a fierce internal agency struggle pitting officials whose careers and reputations were built on the old analysis of the Iraqis as a feckless, inert and inward-looking bunch of thugs against those willing to take a fresh, untilted look at all the evidence.

One breeze of change came in President Bush's Oct. 7 speech in Cincinnati. Among the terror-related items that were declassified for the speech was an agency finding that Iraq is developing "a growing fleet of manned and unmanned aerial vehicles" to deliver chemical and biological weapons on U.S. targets.

That was new stuff, delivered by a determined and effective CIA collection effort earlier this year. Agency information also allowed the president to assert (accurately) that "Iraq has trained al-Qaeda members in bomb-making and poisons and deadly gases."

That's actually old new stuff, stored in CIA files since the mid-1990s. But that intelligence was quietly buried during the Clinton years, when the need not to know very much about Iraq and terrorism was very strong.

This is how war is waged inside the CIA: The upstarts who are challenging the agency's long-standing and deeply flawed analysis of Iraq are being accused of "politicizing intelligence," a label that is a reputation-killer in the intelligence world. It is also a protective shield for analysts who do not want, any more than the rest of us, to acknowledge that they have been profoundly and damagingly mistaken.

The "politicization" accusation suggests that those who find Iraqi links to al Qaeda are primarily interested in currying favor with the Bush White House. It comes primarily from those who won favor in the Clinton years with an analysis based on the proposition that an Arab nationalist such as Saddam Hussein would never cooperate with the Islamic fanatics of al Qaeda. They are now out in the cold in the Bush-Rumsfeld-Wolfowitz era.

Their work is only one part of a monumental record of failure on Iraq by the CIA, which has at different moments sought to understand, support, co-opt and then overthrow Hussein. The agency succeeded in none. Considering the extent of that failure, it is no surprise that Bush has until now relied little on the Langley agency for his information on Iraq. There is simply no way to reconcile what the CIA has said on the record and in leaks with the positions Bush has taken on Iraq.

One year before Hussein invaded Kuwait in 1990, the agency produced a National Intelligence Estimate saying that Iraq was too exhausted and internally occupied to think about war. A supervisor's request to analysts to take a second look at those findings triggered accusations of "politicizing intelligence," says a former CIA official involved in that debate. The mistaken view prevailed and guided the CIA's assessment in July 1990 that no invasion of Kuwait was about to occur.

Such misjudgments have continued until today. After four months of inconclusive debate following Sept. 11, the agency produced a new analysis last spring titled: "Iraq and al Qaeda: A Murky Relationship." It fails to make much of a case for anything, I am told. It echoes the views of Paul Pillar, the national intelligence officer for the Middle East and South Asia, and other analysts who have consistently expressed doubts that Iraq has engaged in international terrorism or trained others to do so since 1993.

More damaging to their case than the accumulating new evidence to the contrary is "old" information long available in CIA files: Iraqi intelligence officers meeting in Khartoum and Kandahar with Osama bin Laden, the nonaggression pact Saddam and Osama reached in 1993, training in Baghdad for international terrorism and the multiple trips to Prague made by Mohamed Atta, the head of the Sept. 11 suicide squads, are all there. These specific reports and much more have been explained away and minimized rather than thoroughly investigated.

Congress should not expect the CIA "to be 100 percent flawless all the time," Director George Tenet complained defensively on Thursday as he was buffeted by questions about the agency's failure to anticipate Sept. 11. The problem is broader, he said: "The country's mind-set has to be changed fundamentally."

The man has a point. But Congress can reasonably expect the agency not to be wrong close to 100 percent all the time on such an important subject as Iraq.

And the place for Tenet to start changing mind-sets is right there at Langley. Unless, of course, he agrees with that mind-set.