General David Petraeus

With a storied career that includes leading coalition forces and counterinsurgency efforts in Iraq and Afghanistan, Retired Army Gen. David Petraeus definitely knows a thing or two about leadership. According to Petraeus, effective leaders don't dictate the tactics; they establish the mission, boundaries and direction, then empower the team to determine the best route. Great leaders also understand that, sometimes, big ideas need to evolve — whether they're running a military operation or private-sector company.