Then-CIA Director David Petraeus testifies on worldwide threats before the Senate Select Committee on Intelligence, on Jan. 31. Zhang Jun/Xinhua /Landov hide caption

itoggle caption Zhang Jun/Xinhua /Landov

Then-Army Gen. David Petraeus (left) and Marine Corps Gen. John Allen in August, 2011. Chip Somodevilla/Getty Images hide caption

itoggle caption Chip Somodevilla/Getty Images