Soon after coming to office, President Obama made it clear that killing or capturing Osama bin Laden was one of his highest national-security priorities.
But it wasn’t until last summer that intelligence officials caught a break in their pursuit of al-Qaida's leader.
Numerous behind-the-scenes accounts of the killing of bin Laden have been flowing since Sunday night's stunning announcement of his death, some of them contradictory. Here is what National Journal knows now:
(RELATED: The updating the narrative on the raid)
In September 2010, the CIA presented Obama with a set of assessments that indicated bin Laden could be hiding in a compound in northwest Pakistan. Starting in mid-March, the president convened at least nine National Security Council meetings to discuss the intelligence suggesting that bin Laden was possibly hiding out virtually in plain sight.
The CIA developed its theory of bin Laden whereabouts through leads gained from al-Qaida’s inner circle and from fighters captured after September 11. Intelligence officials were repeatedly told about one courier working for bin Laden as someone that America’s most-wanted man deeply trusted.
The detainees provided the courier’s nickname to U.S. officials and identified him as a protégé of Khalid Sheikh Mohammed and a trusted assistant of Abu Faraj al-Libbi, once al-Qaida’s third-highest-ranking official (he was captured in 2005). Intelligence officials identified the courier's name four years ago, but it took two more years to zero in on areas of Pakistan where he and his brother operated.
Finally in August 2010, they were able to track him down to the sprawling compound in Abbottabad, a relatively affluent enclave favored by retired Pakistani military, a senior administration official said. The compound was massive and tightly guarded with only two points of access which raised American suspicions that it was more than some Pakistani General's retirement home.
"The physical security measures of the compound are extraordinary," a senior administration official said. "It has 12- to 18-foot walls topped with barbed wire.... Internal walls sectioned off different portions of the compound to provide extra privacy.... The residents of the compound burn their trash, unlike their neighbors, who put the trash out for collection."
Bin Laden and his family were living on the top two floors of the three-story structure, the most prominent building on the property. The compound had neither Internet nor telephone access which was unusual, to say the least, since the property was estimated by American officials to be worth approximately $1 million.
"Many of his terrorist associates in other parts of Pakistan and throughout the region are living in much more dire conditions," a senior administration official said. "You have to be wondering what they’re thinking at this moment when they see that their leader was living, relatively speaking, high on the hog." In the hours since bin Laden's killing, American officials have clearly pointed to his quarters to dispirit al-Qaida forces and Taliban sympathizers who might lament their woeful conditions on the battlefield while their leader, rather than roughing it in some cave, as many had long believed, lived like a wealthy Pakistani mansion.
Intelligence analysts studied the compound, which was built in 2005, carefully. While convinced that a high-value target was staying there, they assessed whether it could be someone other than bin Laden, perhaps his second-in-command, Ayman al-Zawahiri.
"We conducted red-team exercises and other forms of alternative analysis to check our work," the senior administration official said. "No other candidate fit the bill as well as bin Laden did."
The president finally gave the order on Friday morning for the operation to pursue bin Laden—just before he departed for Alabama to visit areas ravaged by last week’s tornadoes, a senior administration official said.
Early Sunday morning in Pakistan, the strike began.
The team that killed Osama bin Laden would have taken him alive if it had the chance, said John Brennan, a counterterrrorism adviser to Obama, but he said administration officials were doubtful that bin Laden would go down without a fight.
"If we had the opportunity to take him alive, we would have done that,” said Brennan, adding that the president “put a premium on making sure that our personnel were protected” during the raid.
TOP STORIES: Pictures–The World Reacts
Newspapers' Front Pages
Secret Team That Killed Bin Laden
PICTURES: WH Correspondents' Dinner
George W. Bush's Statement on Bin Laden
Officials React to Bin Laden's Death
(MAP: Where bin Laden Was Killed)
By 1 p.m. in Washington on Sunday, top advisers had gathered at the White House. Around 2 p.m., shortly after returning to the White House after playing nine holes of golf, Obama huddled with them to review final preparations for the operation. He returned to the Situation Room at 3:32 p.m. for another update, and by 3:50 p.m. he was given word that bin Laden was “tentatively identified” as among those killed in the operation.
More information trickled in indicating that it was indeed bin Laden—including preliminary DNA analysis, Brennan said. At 7 p.m., Obama was told it was a “high probability” that it was, indeed, bin Laden.
"We got him," Obama declared, according to Brennan, after he was confident that U.S. forces captured the terrorist.
The entire operation took just 40 minutes and involved a small U.S. team of commandos, a senior administration official said.
The detachment of Navy SEALs earmarked for the mission spent most of April practicing the assault at a secret base inside neighboring Afghanistan, according to a senior military official with direct knowledge of their preparations. The SEALs constructed a full-scale mock-up of the compound to practice the most effective ways of breaching its perimeter and assaulting various numbers of defenders, the official said. During the weeks of preparations, the compound in Pakistan was kept under round-the-clock surveillance by the U.S., but the official declined to say what combination of drones, aircraft, or satellites was used to monitor the target site. The SEALs, meanwhile, were kept in a constant state of readiness in case the order came to launch the mission sooner than expected because of signs that bin Laden was preparing to depart the fortified building, the official said.