The next Petraeus What makes a visionary commander, and why the military isn’t producing more of them

President Obama recently demoted General David Petraeus, the man who led the turnaround in Iraq and is widely acknowledged to be the most effective military officer of his generation.In June, the president needed a new commander to lead the war effort in Afghanistan, after General Stanley McChrystal spoke too openly with a Rolling Stone reporter and was forced to resign. And, while few may realize this, when Petraeus was appointed to take over in Afghanistan, he was replacing a subordinate. Petraeus may yet be hailed for saving the day. But he also got a new boss and moved one step down the chain of command.

How does this happen to the best our military has to offer? Why was there no other general to take the job?