A new book by Peter Bergen reveals the exhaustive search and daring operation that led to the death of Osama bin Laden, the mastermind of the Sept. 11 attacks who was killed a year ago in a U.S. raid on the al-Qaeda leader's secret compound in Abbottabad, Pakistan.

In an interview with Anna Maria Tremonti on CBC Radio’s The Current, Bergen talks about Manhunt: The Ten-Year Search for Bin Laden, from 9/11 to Abbottabad.

Bergen is one of the few Western journalists to have interviewed bin Laden, and the only one to have seen inside the compound where the world’s most wanted man ended his days. 

Bergen, who has spent years studying bin Laden, says he entered the room where bin Laden died expecting it to be something like entering Hitler’s bunker.

Instead, he says, "I just didn’t really feel anything." Looking around the room, "I could see on the ceiling where the U.S. Navy SEAL had shot him in the head, and the blood had spurted up on the ceiling."

But for the most part, he says, "the whole thing was a scene of squalid, suburban life. He was not living large. He was paying the people who were looking after him $100 a month, money was tight. He had his three wives … and a dozen kids and grandkids and they were all living cheek by jowl. Their beds were hammered together with cheap plywood."

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An undated file photo shows al-Qaeda leader Osama bin Laden, in Afghanistan. (Associated Press)

Bergen says the compound was more like a "makeshift long-term camping site, not the sort of lair of some Dr. No type or Dr. Evil."

Meticulous work by analysts, many of them women working behind the scenes, eventually helped track bin Laden’s courier to the Abbottabad compound.

"Coercive interrogations" by the CIA had also provided information in the hunt, but also disinformation, Bergen notes.

It had not been certain that the al-Qaeda leader was living in the Abbottabad compound before the raid, and U.S. President Barack Obama had assessed the odds at being 50/50.

"In the end, the president made an incredibly tough and I think … courageous call to say, 'Look, we’re going to go in and we’re going to do this,'" says Bergen. 

Tune in to The Current at 8:37 a.m. for the full interview with Bergen.