WASHINGTON, 16 December 2003 — Despite calls for his speedy trial and execution, Saddam Hussein is likely to spend months, if not years, in isolation and under interrogation by US military and CIA officials, government sources said Sunday.

Saddam, who is expected to be kept in Iraq, has already surprised his captors, said two individuals briefed on his first day in captivity. He appeared unexplainably disoriented, which came as a big surprise to US authorities, said several intelligence experts. His handlers are trying to determine whether he was simply fearful or in a debilitated or delusional mental state.

US intelligence officials have learned through the interrogations of top Al-Qaeda terrorists, in particular, to expect months to pass before they can begin breaking down Saddam through psychological and physical stress, US intelligence officials and experts said. “There will be a lot of exploratory conversations with him. I would not expect this to happen quickly,’’ said Rep. Porter Goss, R-Fla., chairman of the House intelligence committee and one of a handful of members who have been briefed on Saddam’s capture. “He has a long history of denial and deception.’’ One former CIA operative in contact with current officials termed the process “a long haul’’ that will involve “simultaneous interrogations,’’ in which information Saddam provides is given immediately to cooperating former high-ranking officials in captivity, and then fed swiftly back to his interrogators to use to prod him further.

Although described as talkative by US military commanders, Saddam was also defiant and unrepentant, according to members of the Iraqi Governing Council, leading authorities to believe that one of the world’s wiliest survivors has a plan for even this stage of his existence.

To deal with the lack of cooperation, some officials involved in supervising his captivity expect to operate under the same guidance, approved by the White House counsel’s office, used in the interrogation of key Al-Qaeda figures such as Khalid Sheik Mohammed, Abu Zubaida and Ramsi Binalshib. The guidelines allow handlers to subject captives to limited pain and discomfort. In some cases they have deprived captives of sleep, restroom facilities and comfortable seating positions. In at least one case, they have denied pain medication.

Those guidelines are likely to be tightened up, said one senior White House official, to come in strict accordance with the Geneva Conventions, because Saddam was a head of state and the top military commander of a country, not a terrorist organization.

Whether Saddam would be captured dead or alive was an active debate within military and intelligence circles. “There was speculation’’ in the intelligence community “that he would not want to be captured,’’ said one senior US government official. Some officials believed he carried suicide belts and poison to commit suicide. They expected he would at least fire his weapon, leading to a fatal retaliation that would have made him a martyr in some Iraqi eyes.

But Saddam did not kill himself with the pistol he was carrying, leading some Saddam analysts to re-evaluate the notion that his place in Arab history is more important to him than his personal comfort and safety. Saddam’s questioning is being conducted by CIA and military interrogators trained on a wide array of tactics —from feigned charm to intimidation. They have, as Goss put it, “several yellow pages of questions’’ to put to the former Iraqi leader. They are currently focusing on his knowledge of any specific operations planned against US troops or civilians in Iraq, and on his knowledge of the how the resistance is organized and supplied.

Interrogators want to quickly figure out “whether he is the evil mastermind who knows every twist and turn of the resistance or is he just in touch with a small number of people and doesn’t have much actionable intelligence,’’ said Daniel Byman, a Middle East analyst at Georgetown University.

Next on the list are questions about terrorist operations and networks operating outside Iraq and information about weapons of mass destruction, officials said. Although intelligence experts inside the administration and on Capitol Hill believe he may not know the whole picture, his capture may induce scientists and former military officers associated with the weapons programs to come forward with information they have withheld while Saddam remained at large.