From a recent Anderson Cooper 360 broadcast, originating Over There:

COOPER: Michael Ware, Petraeus said that as many as 30,000 troops could leave by the beginning of next summer. It was sort of presented as though that was an operational decision.

In truth, it is really an operational necessity. The U.S. can’t maintain these current troop levels, without putting even more strain on the — on our already strained troops. Is that correct?

WARE: Yes, that is correct, Anderson. In fact, I’m struck by the way people are regarding General Petraeus’ discussion of — of those troop levels until July of next year. People are acting like he has just announced some sort of phased withdrawal. Well, no, not at all. That was the timeline for the so-called surge in the beginning.

Indeed, it wasn’t a surge. It was a one-year escalation of U.S. forces. And the clock was due to run out on that escalation in the summer of next year anyway. So, that is not a revelation at all.