Michele Asselin / Contour / Getty Images for TIME

In his first interview since commanding the mission to kill Osama bin Laden, CIA chief Leon Panetta tells TIME that U.S. officials feared that Pakistan could have undermined the operation by leaking word to its targets. Long before Panetta ordered Vice Admiral William McRaven, head of the Joint Special Forces Command, to undertake the mission at 1:22 p.m. on Friday, the CIA had been gaming out how to structure the raid. Months prior, the U.S. had considered expanding the assault to include coordination with other countries, notably Pakistan. But the CIA ruled out participating with its nominal South Asian ally early on because “it was decided that any effort to work with the Pakistanis could jeopardize the mission. They might alert the targets,” Panetta says.

The U.S. also considered running a high-altitude bombing raid from B-2 bombers or launching a “direct shot” with cruise missiles but ruled out those options because of the possibility of “too much collateral,” Panetta says. The direct-shot option was still on the table as late as last Thursday as the CIA and then the White House grappled with how much risk to take on the mission. Waiting for more intelligence also remained a possibility. (See photos of Obama monitoring the bin Laden mission.)

On Tuesday, Panetta assembled a group of 15 aides to assess the credibility of the intelligence they had collected on the compound in Abbottabad where they believed bin Laden was hiding. They had significant “circumstantial evidence” that bin Laden was living there, Panetta says — the residents burned their trash and had extraordinary security measures — but American satellites had not been able to photograph bin Laden or any members of his family. The Tuesday meeting included team leaders from the CIA’s counterterrorism center, the special-activities division (which runs covert operations for the agency) and officials from the office of South Asian analysis.

Panetta wanted to get those aides’ opinions on the potential bin Laden mission, and he quickly found a lack of unanimity among his team. Some of the aides had been involved in the Carter Administration’s effort to go after the hostages held by the Iranians 30 years ago; others had been involved in the ill-fated “Black Hawk Down” raid against Somali warlords in 1993. “What if you go down and you’re in a firefight and the Pakistanis show up and start firing?” Panetta says some worried. “How do you fight your way out?”

But Panetta concluded that the evidence was strong enough to risk the raid, despite the fact that his aides were only 60%-80% confident that bin Laden was there, and decided to make his case to the President. At the key Thursday meeting in which President Obama heard the arguments from his top aides on whether or not to go into Pakistan to kill or capture bin Laden, Panetta admitted that the evidence of bin Laden’s presence at the compound was circumstantial. But “when you put it all together,” Panetta says he told the room, “we have the best evidence since [the 2001 battle of] Tora Bora [where bin Laden was last seen], and that then makes it clear that we have an obligation to act.”

Obama decided that Panetta’s arguments trumped two other options: striking the compound remotely or waiting until more evidence was available to prove bin Laden was there. “If I thought delaying this could in fact produce better intelligence, that would be one thing,” Panetta says he argued, “but because of the nature of the security at the compound, we’re probably at a point where we’ve got the best intelligence we can get.” (See photos of bin Laden’s Pakistan hideout.)

For weeks, Panetta had been pushing the National Geospatial-Intelligence Agency to try to get photographic confirmation of the presence of the bin Laden family. “NGA was terrific at doing analysis on imagery of that compound,” he says, but “I kept struggling to say, ‘Can’t you at least try to get one of the people that looks like [bin Laden]?’ ” NGA produced photographs of the two couriers and their families that McRaven’s Navy Seal team used to identify players in the compound as they made their way toward bin Laden.

Panetta only learned that the President had been convinced by his arguments on Friday, when Obama said he was authorizing the helicopter mission and made his order official in a signed letter. After he received the order, Panetta told McRaven of the President’s decision and instructed him to launch. He told him the mission was “to go in there [and] get bin Laden, and if bin Laden isn’t there, get the hell out!”

CIA officials turned a windowless seventh-floor conference room at Langley into a command center for the mission, and Panetta watched the operation unfold from there. As he and his team waited for McRaven to report on whether bin Laden was indeed at the compound, Panetta says the room was tense. “I kept asking Bill McRaven, ‘O.K., what the hell’s this mean?,’ ” and when McRaven finally said they had ID’d “Geronimo,” the mission code name for bin Laden, “All the air we were holding came out,” Panetta says. When the helicopters left the compound 15 minutes later, the room broke into applause. (See the moment of triumph at the White House.)

The aftermath of the mission has been productive. The U.S. collected an “impressive amount” of material from bin Laden’s compound, including computers and other electronics, Panetta says. Panetta has set up a task force to act on the fresh intelligence. Intelligence reporting suggests that one of bin Laden’s wives who survived the attack has said the family had been living at the compound since 2005, a source tells TIME.

That will raise questions about the Pakistani government’s possible awareness of bin Laden’s location in recent years. But one of Panetta’s predecessors says this can work to U.S. advantage. “It opens up some opportunities for us with Pakistan,” says John McLaughlin, former deputy CIA chief. “They now should feel under some great pressure to be cooperative with us on the remaining issues,” like going after the Taliban elsewhere in the country. “It’s called leverage.”

Read about the CIA’s rare public victory.

How Obama is handling the politics of bin Laden’s death.

America and Pakistan after bin Laden: still “frenemies.”