Ever vigilant about coups and fearful of revolt, Mr. Hussein was deeply distrustful of his own commanders and soldiers, the documents show. He made crucial decisions himself, relied on his sons for military counsel and imposed security measures that had the effect of hobbling his forces.

This has led some American interrogators to theorize that Hussein may have bluffed not only neighboring governments and the United States, but his own restive generals. [...] Former military leaders, including dozens of detained generals who have undergone interrogations, have cited the Iraqi president’s military incompetence, isolation, and reliance on family and tribe in a time of crisis as central factors in the regime’s collapse.

The Iraqi dictator was so secretive and kept information so compartmentalized that his top military leaders were stunned when he told them three months before the war that he had no weapons of mass destruction, and they were demoralized because they had counted on hidden stocks of poison gas or germ weapons for the nation's defense.

Early on, Saddam sought to foster the impression with his generals that Iraq could resist a Coalition ground attack using WMD. Then, in a series of meetings in late 2002, Saddam appears to have reversed course and advised various groups of senior officers and officials that Iraq in fact did not have WMD. His admissions persuaded top commanders that they really would have to fight the United States without recourse to WMD.

Overseen by the Joint Forces Command, an unclassified version of the study is to be made public soon. A classified version was prepared in April 2005. Titled "Iraqi Perspectives on Operation Iraqi Freedom, Major Combat Operations," the study shows that Mr. Hussein discounted the possibility of a full-scale American invasion.

Aziz said Hussein emerged from these diplomatic sessions — some secret at the time — convinced that he might yet avoid a war that would end his regime, despite ample evidence to the contrary.

Of the Iraqi Army, only the Special Republican Guard was permitted inside Baghdad. And an array of restraints were imposed that made it hard for Iraq's military to exercise command.

“There was no unity of command. There were five different armies being used, no cooperation or coordination,” retired Maj. Gen. Abed Mutlaq Jubouri, 63, a former division commander later jailed by Hussein for conspiring against the regime, said in an interview with The Post. “As to the defense of Baghdad, there was no plan.”

While conventional military planning languished, Mr. Hussein's focus on internal threats led to an important innovation: creation of the Fedayeen paramilitary forces. Equipped with AK-47's, rocket propelled grenades and small-caliber weapons, one of their primary roles was to protect Baath Party headquarters and keep the Shiites at bay in the event of a rebellion until more heavily equipped Iraqi troops could crush them.

We expect that Baghdad will be defended by the so-called special republican guard and a variety of other trusted security forces, including an organisation called Fedayeen Saddam and the special security organisation. Honourable members may be interested to know that Saddam Hussein does not trust his regular troops even to enter the city of Baghdad. One of the main roles of the trusted security forces will be to defend against an uprising by the people of Baghdad, who overwhelmingly are part of the oppressed Shiah sect of Islam.

As the war approached, Mr. Hussein took steps to suppress an uprising. Fedayeen paramilitary units were dispersed throughout the south, as were huge stashes of small-caliber weapons. Mr. Hussein divided Iraq into four sectors, each led by a member of his inner circle. The move was intended to help the government fend off challenges to its rule, including an uprising or rioting.

Now, with U.S.-led coalition troops advancing toward Baghdad, Saddam's Fedayeen — whose name means "those ready to sacrifice themselves for Saddam" — are putting up stiff resistance and trying to prevent regular army soldiers from surrendering. ... The result of the Fedayeen activity, intended or not, is to sow suspicion and division between the invading troops and the civilians and stop any uprising against Saddam.