WASHINGTON — Intelligence officers made a crucial discovery this spring after tracking al-Qaeda leader Ayman al-Zawahri to Kabul, Afghanistan: He liked to read alone on the balcony of his safe house early in the morning.
Analysts are looking for that kind of intelligence on life patterns, any habit that the CIA can exploit. In al-Zawahri’s case, his long visits to the balcony gave the agency an opportunity for a clear missile strike that could avert collateral damage.
The hunt for al-Zawahri, one of the world’s most wanted terrorists, dates back to before September 1. 11 attacks. The CIA continued to search for him as he rose to the top of al-Qaeda after the death of Osama bin Laden and the Taliban takeover of Afghanistan last year. And a misstep in the chase, recruiting a double agent, led to one of the bloodiest days in the agency’s history.
Shortly after the US left Kabul, the CIA stepped up efforts to track down al-Zawahri, believing he would attempt to return to Afghanistan. Senior officials had told the White House that they would now be able to maintain and grow networks of informants inside the country, and that the United States would not be blind to terrorist threats there. For the agency, finding al-Zawahri would be a key test of that claim.
This article is based on interviews with current and former US and other officials, independent analysts who have studied the hunt for decades, and others briefed on the events leading up to the weekend strike. Most spoke on condition of anonymity because of the sensitive information used to find al-Zawahri.
For years, al-Zawahri was thought to be hiding in the Pakistan border area, where many al-Qaeda and Taliban leaders took refuge after the US invasion of Afghanistan in late 2001. He was wanted in connection with the 1998 embassy bombings in Tanzania and Kenya and the CIA had tracked a network of people who intelligence officials said supported him.
The examination of this network has intensified with the US exit from Afghanistan last year and the belief among some intelligence officials that senior al-Qaeda leaders would be tempted to return.
The intuition turned out to be right. The agency discovered that al-Zawahri’s family had returned to a safe house in Kabul. Although the family tried to ensure they were not watched and to keep al-Zawahri’s location secret, intelligence agencies soon learned that he too had returned to Afghanistan.
“There was a renewed effort to find out where he was,” said Mick Mulroy, a former CIA officer. “The only good thing that could have come out of the withdrawal from Afghanistan is that some high profile terrorist figures would then think it’s safe for them to be there.”
The shelter belonged to an aide to senior officials from the Haqqani network, a hardened and violent wing of the Taliban government, and was in an area controlled by the group. Senior Taliban leaders met occasionally in the house, but US officials are unsure how many knew the Haqqanis were hiding al-Zawahri.
If some senior Taliban officials were unaware that the Haqqanis had authorized al-Zawahri’s return, his assassination could drive a wedge between the groups, independent analysts and others briefed on the events said.
It is unclear why Al-Zawahri returned to Afghanistan. He had been making recruitment and promotion videos for a long time, and it might have been easier to produce them in Kabul. He may also have had better access to medical care.
Whatever the reason, his ties to leaders of the Haqqani network led US intelligence officials to the hideout.
“The Haqqanis have a very long relationship with al-Qaeda dating back to the days of the mujahideen,” said Dan Hoffman, a former CIA officer. “They are providing al-Qaeda with a lot of tactical support that they need.”
Once the hideout was located, the CIA tracked the playbook it had written during the hunt for bin Laden. The agency built a model of the site and tried to find out everything about it.
Analysts eventually identified a figure who lingered on the balcony reading but never left the house, such as al-Zawahri.
American officials quickly decided to target him, but the location of the house posed problems. It was in the Sherpur district of Kabul, an urban area of houses close together. A missile armed with a large explosive could damage nearby houses. And any kind of incursion by special operations forces would be prohibitively dangerous, limiting the US government’s options for carrying out a strike.
The search for al-Zawahri was of great importance to the agency. After the US invasion of Afghanistan, the CIA base in Khost province became the headquarters of a targeting group dedicated to tracking bin Laden and al-Zawahri. It was one of the leads developed by the CIA to track al-Zawahri that proved disastrous for the agency’s officers at that base, Camp Chapman.
CIA officers recruited Humam Khalil Abu Mulal al-Balawi, a Jordanian doctor and al-Qaeda propagandist, who they hoped would lead them to al-Zawahri. I provided US officials with information about al-Zawahri’s health, convincing them that his intelligence was real. But he was actually a double agent, and on Dec. 30, 2009, I showed up at Camp Chapman with a suicide vest. When it exploded, seven officers were killed.
For many, the attack on Khost intensified efforts to find al-Zawahri. “To honor their legacy, you continue the mission,” Mr. Hoffmann said.
In 2012 and 2013, the CIA focused the hunt on the North Waziristan region of Pakistan. CIA analysts were confident they had found the small village where al-Zawahri was hiding. But intelligence agencies could not find his home in the city of about a dozen compounds, making a raid or drone strike impossible.
Yet the hunt in the United States forced al-Zawahri to remain in the tribal areas of Pakistan, perhaps limiting the effectiveness of his leadership within al-Qaeda.
“Whenever anything related to bin Laden or Zawahri came through the intelligence channels, everyone would stop to step in and help,” said Lisa Maddox, a former CIA analyst. “That was the CIA’s promise to the public: bring them to justice.”
On April 1, senior intelligence officials briefed national security officials at the White House about the safe house and how they had tracked al-Zawahri. After the meeting, the CIA and other intelligence agencies worked to learn more about what they called al-Zawahri’s way of life.
A key idea was that he had never been seen leaving the house and only seemed to get fresh air while standing on a balcony on an upper floor. He stayed on the balcony for long periods, which gave the CIA a good chance to target him.
Al-Zawahri continued to work at the shelter, producing videos for distribution to the Qaeda network.
A senior administration official, who spoke on condition of anonymity to discuss the sensitive decisions that led to the strike, said the information presented to the White House had been vetted multiple times, including by a team independent analysts tasked with identifying everyone staying at the safe house.
As strike options were developed, intelligence officials considered what type of missile could be fired at al-Zawahri without causing major damage to the safe house or the neighborhood surrounding it. They eventually settled on a form of Hellfire missile designed to kill a single person.
CIA Director William J. Burns and other intelligence officials briefed President Biden on July 1, this time with the safe house model, the senior official said.
At that meeting, Mr. Biden asked about the possibility of collateral damage, pushing Mr. Burns to explain to him how the agents had found al-Zawahri and confirmed his information, as well as their plans to kill him.
Mr Biden ordered a series of analyzes to try to predict the strike’s impact on the Taliban, the region and US efforts to move Afghans to the United States, the senior official said. The president also asked about possible risks to Mark R. Frerichs, an American hostage held by the Haqqanis.
In June and July, officials met several times in the Situation Room to discuss intelligence and consider potential ramifications.
CIA plans called for him to use his own drones. Because it was using its own resources, few Pentagon officials were involved in planning the strike, and many senior military officials learned of it shortly before the White House announcement, an official said. .
On July 25, Mr. Biden, happy with the plan, authorized the CIA to carry out the airstrike when the opportunity arose. Sunday morning in Kabul, yes. A CIA-piloted drone found al-Zawahri on his balcony. Agency agents fired the missile, ending a hunt that spanned more than two decades.
Thomas Gibbons-Neff, Adam Goldman and Michael Crowley contributed report.