We like Third World countries to mine and process it as it can be very environmentally unfriendly to do it while being relatively cost effective. The US can do it, but at a much higher cost to do it cleanly.
If the environmentalists really cared about Mother Gaia they would promote mining in the USA where we have rules regarding the environment (and worker safety). Heck, even reduce some of the EPA standards (emissions must be less than 50 ppm instead of 1 ppm) would still be better than most foreign countries.