In his tell-all account, Matt Bissonnette, a Navy SEAL who participated in Operation Neptune Spear to kill the top al-Qaeda leader in Pakistan, says that President Barack Obama and his advisors discussed different options till the last moment.
"The president still had not signed off on the ground- assault option. All we had been authorised to do up to now was to start planning and conduct rehearsals. The White House was still considering an Air Force option, a massive air strike using B-2 Spirit bombers to level the house," writes Bissonnette in "No Easy Day: The Autobiography of a Navy SEAL" using the pseudonym "Mark Owen".
He says Defence Secretary Robert Gates supported the air strike because it kept American ground forces out of Pakistan, which made the mission less like an invasion of the country's sovereignty.
The air strike option required 32 2000-pound smart bombs.
"The barrage would last for a full minute and a half and the crater would penetrate at least 30 feet into the earth in case the compound had a bunker system. The possibility for collateral damage was high, and the possibility of finding identifiable remains after that kind of destruction was low."
The just-released book, published by Penguin, gives fascinating details of the mission undertaken by 22 SEALS, an EOD tech and a CIA interpreter, who flew in two Black Hawk helicopters into Abbottabad, where Pakistan's military academy is located, on the night of May 2, 2011 from a US base in Jalalabad. They killed Osama and four others hiding in a house.