At the end, Petraeus pulled rank on Graham by addressing him as "Colonel" and saying he looks forward to Graham serving (under him) in Afghanistan. (Graham is a Reserves JAG.)
Well that explains it...obvious Petraeus didn’t give him the answer he was looking for. From my perspective it doesn’t look as though there is a date per say...rather a “process” which isn’t a withdrawal of troops. I say stay for whatever duration...better there than on US soil. Keep it all in the ME.