Administration's Counterterrorism Advisor Says Obama's Decision Was Gutsy

John Brennan, the White House's homeland security and counterterrorism advisor, said during a press briefing that President Barack Obama's decision to OK the operation to go after Osama bin Laden in Abbottabad, Pakistan was one of the "gutsiest" of any president.

Brennan said the intelligence the president had to work with was "circumstantial."

"I was a supporter," he said. But the team had "nothing to confirm" that bin Laden was inside the compound.

The president and his cabinet were able to follow the operation in real time, Brennan said. He said some points of the mission were incredibly tense. The president, he said, was worried about the security of the Navy Seals conducting the mission. "It was tense," he said. There was a lot of "holding of breaths and a fair degree of silence."

The most nail-biting moment said Brennan was when the Seals reported that one of the helicopters had malfunctioned. Brennan said it was the one time the operation went to a contingency plan.

Brennan added a few new details to what we already know about the mission: