It's a common misconception that foreign owners of local business exploit the country by keeping all the profits.
I'm not a mining expert, but even if my figures are wildly off base I think I can still make my point. Lets say that the profit of a mining house in Afghanistan is 10%, that means that 90% of all wealth created by the company remains in the country. This is in the form of bought goods and services, labor, and taxes.
So while it is true that all the "profit" leaves the country in a 100% owned American company, most of the wealth stays in the country. No matter how you look at it, extracted minerals will be VASTLY better for Afghanistan than leaving it in the ground. And if they need foreign help to get going so be it.
The way foreign companies have shifted this balance of benefit unfairly in the past is by
a) buying all the goods and services (and a lot of the labor) from their own country
b) paying the locals very low wages
c) selling the product back to themselves at very low prices
This means that very little money is spent INSIDE the country, and very little profit (if any) is made by the sale of product, so no taxes goes to the government. This is pure exploitation and most of the created wealth leaves the country.
Assuming someone learn't from history and negotiates an ethical agreement, this is good for the country. If the government accepts a bribe and allows the above to happen, its a different matter.
American wealth and living standards these days depend on this sort of "shrewd" business negotiations. Where do your responsibility to your stockholders end and your responsibility to foreign citizens begin? What would you be willing to give up in terms of living standards to have the warm fuzzy feeling that someone somewhere in Afghanistan (that probably hates your guts) has something to eat and somewhere to sleep tonight?
It's easy to blame big business, but I've found that the overwhelming majority of people would be even less ethical in their own dealings, and would never accent to the flip side of the coin. "BAN DIRTY OIL COMPANIES!" (but don't DARE raise the cost of fuel for my Hummer!)