The official stressed that no one in intelligence or diplomatic circles opposes the idea of trying to install a democratic government in Iraq.
"It couldn't hurt," the official said. "But to sell [the war] on the basis that this is going to cause 1,000 flowers to bloom is naive."
Some officials said the classified document reflects views that are widely held in the State Department and CIA but that those holding such views have been muzzled in an administration eager to downplay the costs and risks of war.
One intelligence official said the CIA has not been asked to produce its own analysis on the domino question.
At a recent hearing on Capitol Hill, CIA Director George J. Tenet offered a modest assessment of the prospects that overthrowing Hussein could prompt a wave of reform.
"I don't want to be expansive in, you know, a big domino theory about what happens in the rest of the Arab world," Tenet said. "But an Iraq whose territorial integrity has been maintained, that's up and running and functioning ... may actually have some salutary impact across the region."
The State Department report cites "high levels of corruption, serious infrastructure degradation, overpopulation" and other forces causing widespread disenfranchisement in the region.
The report concludes that "political changes conducive to broader and enduring stability throughout the region will be difficult to achieve for a very long time."
Middle East experts said there are other factors working against democratic reform, including a culture that values community and to some extent conformity over individual rights.
"I don't accept the view that the fall of Saddam Hussein is going to prompt quick or even discernible movement toward democratization of the Arab states," said Philip C. Wilcox, director of the Foundation for Middle East Peace and a former top State Department official. "Those countries are held back not by the presence of vicious authoritarian regimes in Baghdad but by a lot of other reasons."
Bush has responded to such assessments by assailing the "soft bigotry of low expectations."
In pushing for democracy in the Middle East, he is departing somewhat from a long track record of U.S. presidents -- focused on preserving stability, economic ties, and access to Middle East oil -- backing autocratic regimes.
Still, the Bush White House has been selective in applying pressure for reform, favoring longtime U.S. allies such as Saudi Arabia and Egypt.
Times staff writer Sonni Efron contributed to this report.