Umar Farouk Abdulmutallab, the Nigerian who tried to bring down a U.S. commercial flight on Christmas Day 2009 by detonating a bomb hidden in his underwear, was sentenced to life in prison Thursday in federal court in Detroit.

U.S. District Court Judge Nancy G. Edmunds said life in prison is a “just punishment,” noting that “the defendant poses a significant ongoing threat to the safety of American citizens everywhere.”

As the flight from Amsterdam carrying 290 passengers and crew approached Detroit, Abdulmutallab tried to detonate the bomb, but it malfunctioned and sparked a small fire. Passengers quickly overpowered him, and the plane, already near the airport, accelerated its descent.

Abdulmutallab’s lawyer had said that sentencing the Nigerian to mandatory life as required under federal law would be unconstitutional because no one was killed in the attempted bombing. But Edmunds was unmoved.

Government lawyers, who played video of the impact of detonating the equivalent amount of explosives as Abdulmutallab carried, essentially said that his failure to succeed in the attack did not lessen its seriousness. They described him as an “unrepentant would-be mass murderer who views his crimes as divinely inspired.”

As the flight from Amsterdam carrying 290 passengers and crew approached Detroit, Abdulmutallab attempted to detonate the device, but it malfunctioned and only sparked a small fire, which led passengers to overpower the bomber. (AP)

Prosecutors said Abdulmutallab, 25, was acting on the orders of Anwar al-Awlaki, the Yemeni American cleric who was killed in a CIA drone strike in September.

Abdulmutallab had gone to Yemen in search of Awlaki and was committed to participating in a suicide mission, according to a Justice Department sentencing memo filed with the court last week.

Awlaki arranged for the Nigerian to meet with the bomb-maker for al-Qaeda’s affiliate in Yemen. Abdulmutallab was instructed not to explode the bomb until he was certain he was over U.S. territory, according to the memo.

U.S. officials said information provided by Abdulmutallab after his arrest illustrated the operational role that Awlaki had in Al-Qaeda in the Arabian Peninsula. And that may have been a critical factor in the legal reasoning in a still-classified Justice Department memo that justified the lethal targeting of Awlaki, a U.S. citizen.

A second U.S. citizen, Samir Khan, who edited AQAP’s magazine, Inspire, was killed in the strike, although he was not a primary target, officials said. Awlaki’s Denver-born 16-year-old son was also killed in an airstrike several weeks after the death of his father.

Abdulmutallab pleaded guilty in October to eight charges, including attempted murder and terrorism, for trying to take down the flight.

Abdulmutallab, the son of a wealthy banker who studied in London, spoke briefly in court Thursday. “Mujaheddin are proud to kill in the name of God. And that is exactly what God told us to do in the Koran,” he said, according to the Associated Press. “Today is a day of victory.”

The Obama administration was criticized by some Republicans for the FBI’s decision to inform Abdulmutallab of his right to an attorney less than an hour into his initial questioning. But officials said he provided enough information to begin dealing with any immediate threat, and he continued to talk in coming months.

“Today’s sentence once again underscores the effectiveness of the criminal justice system in both incapacitating terrorists and gathering valuable intelligence from them,” said Attorney General Eric H. Holder Jr.