(CNN) -- President Barack Obama's decision to order a raid against Osama bin Laden in Pakistan was a courageous and gutsy call, said U.S. Defense Secretary Robert Gates.
"I've worked for a lot of these guys and this is one of the most courageous calls -- decisions -- that I think I've ever seen a president make," he said during a CBS "60 Minutes" interview that aired Sunday night.
"It was a very gutsy call."
The outgoing defense secretary said he had "real reservations" about the intelligence surrounding the raid.
"I was very concerned, frankly," he said. "My worry was the level of uncertainty about whether bin Laden was even in the compound. There wasn't any direct evidence that he was there. It was all circumstantial, but it was the best information that we had since probably 2001."
U.S. officials had tracked a trusted bin Laden courier for years, who they believed was living with and protecting the al Qaeda leader. They were confident the courier lived at the Pakistan compound, but were not certain that bin Laden lived there too.
The courier and his brother were among those killed in the raid.
Gates said it would be "premature" to talk about whether bin Laden's death could accelerate the withdrawal of U.S. troops from Afghanistan, now slated to start in July, but said he believes the United States is gaining the upper hand there.
"We have over the last 18 months put in place, for the first time, the resources necessary to ensure that this threat does not rebuild -- does not re-emerge -- once we're gone. I think we could be in a position by the end of this year where we have turned the corner in Afghanistan," he said.
Gates, the only Cabinet member from the previous administration to stay on when Obama came into office, is expected to step down this year.
Former President George W. Bush nominated Gates as the nation's 22nd secretary of defense in December 2006 to replace Donald Rumsfeld, one of the architects of the Iraq war.
During the early months of his tenure, Gates focused on implementing the "troop surge" in Iraq, a strategy change that was under consideration before he became secretary. It called for increasing the number of troops in Iraq and focusing their efforts in Baghdad. The goal was to have Iraqi troops take the lead in military matters and allow political progress to proceed by isolating extremists.
Although many on both sides of the political spectrum opposed the idea of 20,000 more American troops in Iraq, by 2008 violence declined, and Gates began overseeing the withdrawal of U.S. troops from the country, an endeavor that continues.
"I think had we left here with our tail between our legs, and with chaos, it would have been very bad for our army and for our military," he said.
Still, Gates told CBS that he was worried the United States would be "penny-wise and pound-foolish" in Iraq in the months and years to come.
The defense secretary also lashed out at the institution he runs during the wide-ranging interview, criticizing Pentagon bureaucracy.
"I think the hardest thing for me to deal with is leading a department that is organized to plan for war but not to fight a war. And so everything that I wanted to do to try to help the men and women in the field, I've had to do outside the normal Pentagon bureaucracy ... that's been very frustrating," he said.
"I've ruffled a few feathers at all the institutions I've led, but I think that's part of leadership."