He'll start as CIA director next week, waging war on terrorists in a different way.
Many thought Petraeus would become chairman of the Joint Chiefs of Staff after being credited with turning around the Iraq and Afghanistan wars.
But President Barack Obama asked Petraeus to take the top spy job. That also keeps him from running against Obama for president, though Petraeus insists he has no political aspirations.
Petraeus says he is retiring so there's no confusion over the separation of intelligence and the military.