Federal prosecutors yesterday portrayed convicted terrorist Ahmed Ressam as a duplicitous would-be killer who has reneged on his deal to help America in its war on terrorism.

In court filings, they asked a federal judge to sentence Ressam to 35 years in prison — eight years more than a deal he signed after his conviction.

The government's take on Ressam's cooperation — or lack of it — contrasted sharply with defense pleadings that portrayed the 37-year-old Algerian as a contrite and courageous defector from al-Qaida whose information has saved lives and disrupted Islamic terrorism worldwide. Defense lawyers say Ressam's sentence should be 12 ½ years.

"His decision to end cooperation raises the specter that he continues to pose a real and serious threat to the United States," wrote assistant U.S. attorneys Mark Bartlett and Michael Lang in documents filed yesterday. "Thus, this court must decide at what age would Ressam no longer pose a threat to this country."

Prosecutors say that their suggested 35-year sentence is "extremely generous" and takes into account Ressam's "incomplete cooperation." By their calculations, federal sentencing guidelines should put the would-be Millennium bomber behind bars for a minimum of 65 years.

Ressam's attorneys insist he is still available to testify, if asked.

Ressam is scheduled to appear before U.S. District Judge John Coughenour in Seattle on Wednesday to be sentenced for plotting to set off a suitcase bomb at Los Angeles International Airport during the holidays running up to the Year 2000 celebration. Ressam was arrested Dec. 14, 1999, in Port Angeles with the makings of a powerful bomb in the trunk of his rental car.

Convicted on nine terrorism-related counts in the spring of 2001, Ressam entered into a deal with the government to provide information on what then was a shadowy group known as al-Qaida in exchange for a reduced sentence. In that document, Ressam's attorneys and the government agreed that they would not ask for a sentence of less than 27 years.

But that agreement is not binding on the judge, and Ressam's attorneys now argue that the Sept. 11 attacks — and Ressam's elevated importance as an informant against Osama bin Laden's terrorism network — have made it obsolete.

The defense noted that Ressam has provided invaluable intelligence on al-Qaida's leaders, training and techniques. In the case of his friend and financier, Mohktar Haourari, Ressam's testimony helped secure a conviction and 24-year prison sentence.

But prosecutors now say that Ressam's refusal to cooperate is endangering ongoing cases against two other alleged terrorists: Abu Doha, an alleged al-Qaida lieutenant and recruiter in London who Ressam says oversaw the Algerian section of bin Laden's camps in Afghanistan; and Samir Ait Mohamed, an accused member of a terrorist cell in Montreal who Ressam says once suggested blowing up a gasoline truck in a Jewish neighborhood in that city.

Both men were indicted in New York for helping Ressam further his plot to bomb the Los Angeles airport, but neither has been extradited. Samir Ait Mohamed is in Canada, Abu Doha in London.

"The United States currently finds itself in the extremely difficult situation of trying to proceed with these critical prosecutions after the most significant evidence (Ressam's testimony) has evaporated," prosecutors wrote.

The dispute about Ressam's cooperation is played out in other court records.

The defense has submitted a sealed report by a psychiatrist, Dr. Stuart Grassian, who concluded that Ressam is experiencing "cognitive difficulties as the result of his prolonged solitary confinement," including memory problems.

Prosecutors dismiss Grassian's report as "an interesting assemblage of observations and commentary" by someone whose research has come under attack.

Moreover, they contend that Ressam has hardly been locked away and alone. "This court must acknowledge that Ressam's time in solitary confinement was limited in duration and, for a significant portion of time, at his request." Since April 2004, they say, he has been in the Bureau of Prisons' "witness security program," where he is not in solitary confinement.

The two sides even disagree on the message a reduced or lengthy sentence for Ressam might send.

Defense attorneys argue that his trial was a "national showcase" that demonstrated how the United States could prosecute acts of terrorism fairly and openly through the judicial system. By treating Ressam fairly, the attorneys say, prosecutors were able to gain his cooperation, and thus valuable intelligence and his testimony at future trials.

In making the case for a lighter sentence, Ressam's lawyers cite numerous other cases both in the United States and Europe in which terrorists convicted of crimes that did not result in anyone's death often received sentences of 12 or fewer years.

Prosecutors offered a starkly different view. They say Ressam's efforts to bomb the airport could have claimed the lives of hundreds of people, and that justice demands "an unfaltering response" to Ressam's "heinous goal."

Terrorists "are seeking to tear the fabric that binds the people of our nation together, and the nations of the world together," prosecutors wrote. When they are caught, they should be tried fairly and, if convicted, "held fully accountable for their crimes," they wrote.

Mike Carter: 206-464-3706 or mcarter@seattletimes.com