In late summer 2010, at the end of a morning briefing, one of President Obama's security advisers said, "Mr. President, Leon and the guys at Langley think they may have come up with something." The adviser was referring to then-CIA Director Leon Panetta, and to a possible lead on the country's most wanted terrorist: Osama bin Laden.
It was hardly the first time there had been an enticing lead. But this small scrap of intelligence turned out to be a breakthrough. Mark Bowden describes the scene in his new book, The Finish: The Killing of Osama bin Laden — and he details everything that it took to get to that moment, from presidential briefings to the history of drones.
Bowden, whose previous books include Black Hawk Down, tells NPR's Renee Montagne that the nature of warfare has changed dramatically since the terrorist attacks of Sept. 11, 2001. "The United States military and intelligence apparatus was, certainly in 2001, still a product of the Cold War," he says.
"The enemy that we faced during the Cold War was the U.S.S.R. and countries that could potentially pose a threat to the United States; and their missile silos, their bases and whatnot were very easy to find, but were pretty much hard targets," he says.
By contrast, Bowden says, the men behind Sept. 11 were relatively unguarded — but fantastically difficult to track down.
Computers played an enormous role in "connecting the dots" in the hunt for terrorists, Bowden says, partly because they're great at picking patterns out of chaos.
"So, literally, the United States began, very soon after 9/11, essentially throwing every scrap of data into an enormous database, and then went about developing software that can sort through this enormous database, and also make sense out of lots of different kinds of data," he says.
Computers made it easy, for example, to monitor the movements of a terrorist organization by tracking the trips made by its vehicles.
"I think speed is also crucial here," Bowden says. "A team of special operators in Iraq suddenly could conduct a raid, and within minutes of that raid have secondary targets given to them from information they gathered on site, which enabled them to get inside what they call the 'information cycle' of the enemy. So this is just extremely helpful and really started taking apart al-Qaida."
It was that technology, that speed, that helped U.S. forces catch up to bin Laden, when the CIA managed to track a man who appeared to be serving as a courier for bin laden.
"He ... and his brother, who both lived on that compound, took extraordinary precautions, you know. They would burn their garbage on site, they would drive for an hour or more away from the compound before they would make a phone call. When they got on the phone to even their closest family members, they lied about what country they were in or where they were," Bowden says. "And so those were all suspicious things. And then when they looked at the size of the compound in Abbotabad, they realized that there was possibly someone other than the brothers themselves hiding there."
In that compound, bin Laden was living a simple, cramped and lonely life. "Other than going outside and pacing in the garden, he never really left," Bowden says. "There were people living in that compound who had never seen him before. So he was about as deep into hiding as you can be without actually being in a hole somewhere."
Bowden describes bin Laden's death in detail in The Finish, though his account has been slightly contradicted by one of the Navy SEALs who was on the mission.
"I was actually pretty pleased that it confirmed like 98 percent of what I had learned, but there were some minor discrepancies, and of course the most significant one was the sequence of bullets that actually killed bin Laden," Bowden says. "The minor disparities will be sorted out in time, but essentially, the story hasn't changed that much."