In 2011, on the eve of the ninth anniversary of the 9/11 attacks, the Central Intelligence Agency (CIA) informed then-US President Barack Obama that it had found the best evidence in years that would guide it to the founder of Al Qaeda, Osama bin Laden.

The agency tracked a high-level messenger from Al Qaeda to a house in Ibbad, Pakistan, and they believed that he could guide them to bin Laden's location, only to discover that the latter was living in that house.

Former CIA Director John Brennan, who was Obama's chief adviser on counterterrorism, told AFP about what he described as the "most difficult, secret, and best planned operation" in his career.

High-stakes Special Forces operation in which bin Laden was killed on May 1, 2011.

The "CIA" warned that its intelligence needs to be verified, but there was enthusiasm during a meeting about the possibility of arresting the most important fugitive wanted by the United States.

Over the following months, CIA observers became increasingly certain that the tall bearded person who was seen walking inside the compound, where he was called "Paiser" (meaning the one who walks steadily), was Bin Laden even though they could not see his face clearly.

Options

By late December, Obama was ready to act.

In complete secrecy, White House officials began to contemplate the process, while laying in front of them on the table a model of the compound.

Among the options was a guided missile strike;

Except that it would have left them without evidence that they killed bin Laden.

As for the second option, a helicopter attack on a dark night, it carried very great risks, as American soldiers might be killed in an exchange of fire or they might engage in a confrontation with Pakistani soldiers, who were not informed of the operation.

US administration officials directly monitored the killing of Osama bin Laden in Pakistan (Reuters - Archive)

With preparations reaching advanced stages in early 2011, a senior CIA expert on bin Laden was 70% certain that Paiser was indeed bin Laden, while another evaluation gave this possibility only 40%.

But there was no certainty of identity.

"We certainly didn't have the intelligence that we wanted," Brennan says.

However, he added, "There was nothing to contradict the view that he was bin Laden. This is what we were looking for, any indication that Paiser is someone other than bin Laden."

risk

On Thursday, April 28, 2011, Obama met with senior officials in the White House's underground operations room.

Brennan recalls that "Obama wanted to listen to everyone's views." Among those who rejected the operation were Defense Secretary Robert Gates and Joe Biden, the current US president who was Obama's vice president at the time, but the majority were with the process.

The next morning, Obama gave the green light to the Special Forces on Sunday afternoon US time, as Brennan continued to review the plan.

"You can review it over and over in your head, to make sure not only of what you have done so far, but also of what will happen the next day, and that you were confident that every possible aspect of it was being considered," Brennan said.

Senior security and defense officials gathered in the operations room on Sunday to prepare.

Osama bin Laden was at the top of the most wanted list in the American (French) security and military institutions.

As the helicopters departed from Afghanistan on a 90-minute flight to Ibbad, officials gathered in a side room where Major General Brad Webb monitored the events from a laptop while he was communicating directly with Special Operations Commander Major Bill McCraven.

A famous photo from the White House shows Obama, Biden, Brennan and other officials gathered around the Web, while they silently monitor the events of the operation via video.

'Achievement of an achievement'

One of the helicopters crashed while landing, another was to be sent for support, and there was no video transmission from within the complex itself.

After about 20 minutes, "Macrieven received from the attackers the phrase Geronimo Geronimo", according to Brennan.

Which means bin Laden was killed.

Brennan recalls that the first reaction was relief. "There was no applause or celebration. The feeling was that an achievement was accomplished," Brennan recalls.

Brennan admits that the operation was fraught with risks. "But as the president said, even if the chances were 50-50, it was the best chance the United States had ever had to capture bin Laden."

"It was definitely the right risk that had to be taken at the right time," he asserts.