The future of America's targeted assassination program will depend on how the 25-year agency veteran, its guiding presence, decides to approach it.

Pete Souza/The White House

You might not know John Brennan's name yet, but that's about to change. And even if you don't know who he is, you're almost certainly familiar with his work: If you've heard about any drone strike over the last four years, you've witnessed his hidden hand. Brennan, currently President Obama's chief counterterrorism adviser, is the driving force behind America's overseas drone program. And if the president has his way, Brennan will soon be the director of the CIA, replacing General David Petraeus.

For Petraeus, the move from commanding U.S. troops in Iraq and Afghanistan to leading the CIA provided an opportunity to continue to pursue the small-footprint, assassination-focused method of prosecuting the war on terror that he'd worked hard to implement from within the Army. For Brennan, a move to the top of the CIA could signal the evolution of the drone program, which he has both overseen and sought to reign in.

If he's confirmed, it won't be Brennan's first tour of duty in Langley. He spent 25 years at the agency, including time as station chief in Saudi Arabia; he's also a fluent Arabic speaker. (Incredibly, he applied to work at the CIA after seeing a want ad in the New York Times.) It's also not his first bid for the director's chair: After Obama's 2008 victory, Brennan was a leading contender for the job, but he withdrew his name after pressure from liberals and civil libertarians over his role in so-called "enhanced interrogation tactics" -- read torture -- while heading the National Counterterrorism Center during the Bush Administration.