Gen. David Petraeus was sworn in Tuesday as director of the CIA, bringing his celebrated 37-year career in the Army to a close. Petraeus takes over at a moment when roles of the CIA and the military are more and more tangled, with the spy agency running covert drone-missile operations in far-flung corners of the Arab world. Petraeus has been involved in strategy for both the Iraq and Afghanistan wars, and was moved to the CIA as part of an administration shakeup of top military leadership. He took his oath with Vice President Joe Biden on Tuesday morning and went directly into his first security briefing with President Obama. "There is literally no time to waste. The president wants him on the job," Biden said.