What's a good book about the history of Afghanistan?

I'm looking for a good, comprehensive, general history of Afghanistan. I'd prefer something relatively new--but something within the last 40 years or so that's very good trumps that! A good read is always welcome, but, again, I want to learn about Afghanistan comprehensively, and that criteria trumps a good read. Length doesn't scare me, although I probably want to avoid multi-volume, unless there's a very good reason to get it. Answers, please, from those who really know what they are talking about. Thanks so much.