The "underwear bomber" has pleaded guilty to trying to blow up a US-bound airliner on Christmas Day 2009, saying he had sought to avenge the killing of innocent Muslims.
In a six-minute speech to a shocked courtroom on the second day of his high profile-trial in Detroit, Michigan, Umar Farouk Abdulmutallab insisted his actions were righteous and that the true crime was US foreign policy.
"I am guilty of this count in US law but not in the Koran," the 25-year-old Nigerian said as he confessed to trying to kill 289 people on a packed transatlantic airliner using explosives hidden in his underwear.
"The United States should be warned that if they continue and persist in promoting the blasphemy of Mohammed and the US continues to kill and support those who kill innocent Muslims then the US should await a great calamity through the hands of the Mujahedeen... or God."
The botched plot, which US officials say was the work of al-Qaeda in the Arabian Peninsula, failed because the explosives did not fully detonate and instead caused a fireball.
Passengers and crew members were able to restrain Abdulmutallab and put out the fire as the Northwest flight from Amsterdam made an emergency landing in Detroit on December 25, 2009.
Since many of the counts Abdulmutallab pleaded guilty to carry mandatory minimum sentences of 30 years without parole which must be served consecutively, he is expected to spend the rest of his life behind bars.
Abdulmutallab kept his description of how he carried out the plot to the absolute minimum required to satisfy the judge that he was indeed guilty of all charges.
Reading calmly from a prepared speech, he stood straight in a black skullcap, gold tunic and blazer.
Abdulmutallab said he "had an agreement with at least one person" to attack the US in retaliation for US support for Israel and in revenge for the killing of innocent Muslims in Palestine, Yemen, Iraq, Somalia, Afghanistan and beyond.
"I carried with me an explosive device onto Flight Northwest 253, again to avenge my fellow Muslims," said Abdulmutallab, who has confirmed that he travelled to Yemen for al-Qaeda training prior to the attack.
"I attempted to use an explosive device, which under US law is called a weapon of mass destruction, which I call a blessed weapon to save the lives of innocent Muslims for the US used weapons of mass destruction on innocent Muslims," he told the court.
"If I said I did it, but the American people are guilty of the sin and (President Barack) Obama should pay for the crime the court would not accept that," he said.
"However, according to US law which is unjust... my actions make me guilty to a crime."
The botched operation triggered global alarm and led the United States to adopt stringent new screening and security measures, including controversial pat-downs at airports and a massive expansion of the no-fly list.
It also cast a spotlight on Yemen, where al-Qaeda in the Arabian Peninsula (AQAP) is increasingly seen by US officials as a threat comparable to the terror network's core leadership in Pakistan and Afghanistan.
The reputation of the US intelligence services also took a hit because Abdulmutallab's father, a prominent Nigerian banker, had warned the CIA about his son's growing radicalisation.
Abdulmutallab's calm and respectful demeanour today was in sharp contrast to his disruptive behaviour during jury selection.
This was marked by incendiary outbursts, including a pledge that militants will wipe out "the cancer US," and praise for radical al-Qaeda cleric Anwar al-Awlaqi and former leader Osama bin Laden, both killed in US raids.
Abdulmutallab is to be sentenced on January 12.
