A recent walk-on in the Military Industrial Complex Conspiracy Cavalcade is just in time to supplant the Michael Moore absurdity about natural gas pipelines as the Real Reason (tm) for going into Afghanistan. Namely, the discovery of A TRILLION DOLLARS OF PRECIOUS MINERALS!!!1!!1!
Yes, I've been aware of the apparently prodigious mineral finds in Afghanistan since 2010. To the best of my knowledge, there is still insufficient data to confidently support the claims which are made about these discoveries. VERY promising-looking outcrops of mineralized rock have been spotted, but they have not yet been fully characterized as to their extent or purity (and thus their value, regardless of amount). It is not at all uncommon for substantial surface outcroppings to represent the last remains of past deposits which have eroded away, leaving only the *bottom* and not the *top* of a once-rich mineral concentration.
Getting this information is a laborious and hardware-intensive process of drilling and sampling and drilling some more. So, it is not surprising that it took until last year to get any "ground truth" on the deposits. It does look very good so far...but there are non-trivial issues in proceeding to extraction (lining up bidders to undertake these vast projects in the arid, infrastructure-lean, frequently-embattled --especially in the South, where most of the rare earth metals are-- land-locked primordial moonscape of a "country." And that's not even getting into the near-certainty of enormous corruption and very messy jostling by regional warlords to control the most promising territories).
In short, this thing is a long way from a paycheck.
As for why there were geologists with the Army ("Proof! PROOF!! I say, that all is going as They have Foreseen!"): it is SOP for a battlespace to be characterized in minute topographical detail, via aerial and orbital reconnaissance, in preparation for insertion of forces. This becomes even more critical when supply lines are VERY limited in their access to personnel who must combat a foe who is, himself, widely distributed around a *most* unforgiving AO. Given the extent of the deposits --as evident in the USGS map in the article I linked above-- it is not the least bit surprising (nor does it make it at all necessary to posit some shadily mercenary intent), that these surveys would also have revealed these VERY attention-grabbing mineralogical aspects of the landscape.
Sometimes a cigar is just a cigar.