Something to add to the discussion:
This excludes many valuable minerals, but it gives you an idea of the value Afghani land holds in terms of some more common minerals. Also, look into Goldman's purchase of mining rights on various plots in Afghanistan. Detailed information is hard to find, but there is some out there. I have a much more precise map including REM's and Li on my computer somewhere, I'll try to find it. On top of this, Afghanistan's location is extremely valuable. It's no coincidence the Russians went after Afghanistan and even less coincidence we made sure they didn't win.