CNN Special Report: WE GOT HIM: Obama, Bin Laden, & The War On Terror

On the fifth anniversary of Osama bin Laden's death, President Barack Obama sharply defended his targeted approached to fighting terror -- and said the next president would most likely follow his lead rather than his predecessor's.

While Obama spoke with confidence of the decision to launch the raid despite the odds being "probably 50/50" that that the U.S. was correct that the target in the Abbottabad, Pakistan, compound it was tracking was bin Laden, he did speak about the difficulty in making wrenching decisions, especially with the expanded use of drones during his presidency.

Unmanned aircraft have become an invaluable tool in areas tough to reach with U.S. soldiers, Obama said. Within the first two years of his presidency, though, Obama said he felt the legal architecture and control systems in place to use them weren't enough.

"It became so easy to use them without thinking through all the ramifications," he said. "What we've tried to do is make sure that we are accountable at the highest levels for how we're using Predators."

The standard is of "near certainty" that the target is an active terrorist threat and that civilian casualties are being avoided, the President said.

"Having said that, you always lose sleep because you know there's always the possibility in a kinetic action that somebody who shouldn't be killed is killed," he said.Obama said it wasn't until the helicopters had landed in Afghanistan with bin Laden's body "that all of us breathed ... a sigh of relief."