The admitted mastermind of a foiled plot to bomb New York City subways testified Tuesday that he wanted to fight jihad in Afghanistan after coming to believe that the U.S. government was behind the Sept. 11, 2001, attacks.

Najibullah Zazi told a federal jury that he and two friends made an oath about five years ago to leave their Queens neighborhood and "fight alongside the Taliban" after listening to the recorded sermons of radical Muslim clerics.

The men had decided that complaining about American intervention in Afghanistan wasn't enough, he said.

"We decided we were not doing our jobs," Zazi said. "We shouldn't just point fingers."

At that time, he said, "My view was that 9/11, who was behind it, was America itself."

The 26-year-old former Colorado air shuttle driver, his long beard cut short from the time of his 2009 arrest, was testifying for the first time since his 2009 arrest at the trial of Adis Medunjanin, his alleged accomplice in what authorities have called one of the most frightening near-miss plots since the 9/11 attack.

Medunjanin, 27, a Bosnian-born Muslim and naturalized U.S. citizen, has pleaded not guilty in U.S. District Court in Brooklyn to conspiracy to use weapons of mass destruction, providing material support to a terrorist organization and other charges.

Prosecutors allege that Zazi, Medunjanin and Zarein Ahmedzay traveled to Pakistan in 2008 to try to join the Taliban, but were instead recruited by al-Qaida operatives for a suicide mission on U.S. soil.

Ahmedzay, who has also pleaded guilty, testified on Monday that the three former high school classmates made a pact "to go to Afghanistan and fight with the mujahedeen against American forces."

Zazi, who used beauty supplies to try and cook up explosives in a Colorado hotel room, was stopped shortly before the eighth anniversary in a traffic stop after driving cross-country to New York City. He was arrested days later after returning to Colorado.

He pleaded guilty to the plot to strap on suicide bomb vests and detonate them inside Manhattan subways in 2010. He and Ahmedzay agreed to testify against Medunjanin in a bid for leniency.

The men "were prepared to kill themselves and everyone else around them — men, women and children," Assistant U.S. Attorney James Loonam said in opening statements. "These men came so close — within days of carrying out this attack."

In his opening on Monday, defense attorney Robert Gottlieb accused the government of using "inflammatory rhetoric" about al-Qaida and terrorism to prevent jurors "from seeing the truth about this case." The lawyer conceded his client had sought to support the Taliban's struggle against U.S. forces in Afghanistan, but denied he ever agreed to kill American civilians for al-Qaida.

"The truth is that Adis Medunjanin is not a terrorist," he said. "Mr. Medunjanin never planned to bomb the New York City subways."

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