Six weeks before the raid by U.S. Navy SEALs that killed Osama bin Laden last May, President Obama’s top national security officials debated various other options, including dropping an experimental small bomb on the al-Qaeda leader inside his Pakistani fortress, obliterating the compound with a B-2 bomber or inviting the Pakistanis to conduct a joint operation.

While some favored the small bomb option, including then-Defense Secretary Robert M. Gates and Gen. James E. Cartwright, the former vice chairman of the Joint Chiefs of Staff, others persuasively argued that the mini-bomb might miss or that there would be no way to prove to the world that bin Laden had been killed, according to a new book by bin Laden expert Peter Bergen.

“I think we have hung our hopes on sophisticated new technologies sometimes too soon that don’t work out,” Adm. Mike Mullen, then the Joint Chiefs chairman, told Bergen of the March 14 debate within the president’s war cabinet.

The book, “Manhunt. The Ten-Year Search for Bin Laden From 9/11 to Abbottabad,” is scheduled for publication Tuesday, the first anniversary of bin Laden’s death.

In addition to a detailed account of nearly a decade of CIA frustration, spent with virtually no idea of the al-Qaeda leader’s whereabouts, the book describes bin Laden’s six-year stay in Abbottabad until the moment when, according to Bergen, he uttered his final words, spoken to his fourth wife as the commandos climbed the stairs to his bedroom: “Don’t turn on the light.”

Excerpts of the book describing bin Laden’s final days were published online by Time magazine Thursday.

Drawn from now-declassified documents seized by the SEALS from the compound, interviews with senior U.S. policymakers and a visit to the compound itself two weeks before the Pakistani government ordered it destroyed last February, Bergen describes bin Laden’s life in Abbottabad as a “comfortable, if confining retirement” that left him free to ”indulge his hobbies of reading and following the news” attended by three of his wives and surrounded by many of his children.

“For the world’s most wanted fugitive,” he writes, “it was not a bad life.”

The large house, with separate living quarters, including kitchens and baths for two wives, was sparsely furnished and surrounded by high walls that bin Laden apparently never went beyond during the half-decade he lived there. He lived on the third floor with his youngest wife, Amal, 29, who had given birth to the last of their two children in Pakistani hospitals.

The house had no air conditioning and “only a few rudimentary gas heaters,” despite the seasonal temperature extremes of the area. “Beds for the various family members were made from simple planks of plywood,” Bergen writes. “It was as if the compound’s inhabitants were living at a makeshift but long-term campsite.”

For those hunting him, bin Laden became an almost mythical figure, the subject of thousands of mythical “sightings” and theories about his whereabouts, none of which panned out. As have other accounts, Bergen presents a persuasive case that the opportunity to capture or kill bin Laden before his escape from his Tora Bora hideout in the Afghan mountains was lost when U.S. military leaders and the Bush administration failed to approve requests from military and CIA operatives on the ground for reinforcements.

Bush, Bergen writes, was “incensed” when Michael Morell, his CIA briefer, told him in early 2002 that bin Laden had survived the Tora Bora attacks, and “became hostile, as if Morell himself were the culprit.”

In 2005, Bergen reports, a paper written by a CIA analyst became the guide for the ultimately successful hunt. With the absence of any plausible leads after nearly four years, the analyst proposed building the search on four “pillars” — bin Laden’s family, his communications with top al-Qaeda leaders, his occasional outreach to the media and his use of a courier network.

It was the now widely known discovery and years-long tracking of the courier Abu Ahmed al-Kuwaiti, who lived inside the compound with bin Laden, that ultimately cracked the case.

As they debated how to find out whether bin Laden was inside, the CIA discussed numerous proposals.

“One idea was to throw in foul-smelling stink bombs to flush out the occupants,” Bergen says. Another was to use loudspeakers outside to broadcast from a purported “voice of Allah” commanding them to come into the street. Others proposed establishing a nearby safe house. That idea was adopted but provided agents with little information about what, or who, was inside.

When Obama met with his top aides April 28, two days before the raid, both Gates and Vice President Biden reiterated their opposition to the operation as too risky. Bergen writes that they argued that the evidence of bin Laden’s presence was circumstantial, the mission was too dangerous and relations with Pakistan would be destroyed.

Gates has publicly acknowledged reservations. At the final April 28 White House meeting before the raid, Bergen says, Gates told Obama he would be “more comfortable” with “some kind of precision strike” rather than a commando raid.

After Obama gave the formal go-ahead two days before the May 1 mission, White House aides continued to debate whether he should attend a media dinner the night of the raid and whether his presence in the Situation Room during the operation would give the unwelcome impression that the chief executive was “micromanaging” a military operation.