Peoria: A US judge sentenced al Qaeda sleeper agent Ali al-Marri to more than eight years in prison, rejecting pleas from prosecutors for a much longer jail term.
Judge Michael Mihm expressed fears on Thursday Marri could re-offend but said a "just sentence" must reflect the fact he was designated an "enemy combatant" and forced to spend more than six years in a US Navy brig without charge.
Marri, a 44-year-old dual Saudi-Qatari national, confessed in April to having trained in terrorist camps in Pakistan before being sent to the United States on a mission by September 11 mastermind Khalid Sheikh Mohammed.
"We are defined as a people by how we deal with difficult and unpopular legal issues," Mihm said, before handing down a sentence of eight years and four months at the court in Peoria in the US state of Illinois.
Under a plea bargain with federal prosecutors in April, Marri faced up to 15 years in jail.
With credit for about two years already served in civilian jails, and given the 54 days he could earn each year for good behaviour, Marri might be released as early as 2015 after serving less than six years.
Initially arrested in Illinois on credit card fraud charges, Marri was declared an enemy combatant in 2003 and spent nearly six years in solitary confinement in a military brig in South Carolina without charge.
His case was transferred to civil court on February 26 when he was formally indicted on charges of providing support to al Qaeda and conspiring with others to do the same.
In a tearful and emotional statement before sentencing, Marri -- who admitted in April to conspiring with al Qaeda to carry out a terrorist attack within the United States -- vowed he would never again wish harm upon the American people.
"I am glad I have no blood on my hand and my assistance did not cause any bloodshed or lead to that either, nor would I have ever agreed to that and I will never agree to that in the future, but I am sorry for providing assistance for those who would do this country harm," Marri said, according to a text of his statement published by the Peoria Journal Star.
"Even though I am a changed person from the 2001 al-Marri, I hope you would look with an eye of mercy on me today."
During Thursday`s sentencing the judge was clear about the fact that Marri was likely to re-offend.
"I believe that you have not totally rejected what you did and that you would do it again after you go home, whether here or somewhere else," Mihm said.
Marri`s case has reignited debate over whether an American president should have the authority to detain terror suspects -- including legal US residents -- indefinitely without charge.
Unlike detainees held at the American naval base in Guantanamo Bay, Cuba, Marri was a legal US resident when he was arrested in December 2001 in connection with the 9/11 attacks.
President Barack Obama has eliminated the "enemy combatant" designation and vowed to shut down Guantanamo by January.
Marri admitted in April that he attended several terrorist training camps in Pakistan from 1998 to 2001, according to his plea agreement.
He met Khalid Sheikh Mohammed, considered the architect of the September 11, 2001 attacks, at one of the camps and agreed to go to the United States for an al Qaeda operation.
Marri entered the United States on September 10, 2001 with his wife and children, ostensibly to study at an Illinois university.
The next day al Qaeda launched its attacks, and Marri has said he continued to work for the extremist organisation by researching poisons such as cyanide and the location of dams, waterways and tunnels.