currently not the case, as the US has spun up rare earth metal mines (molycorp, e.g.) also the environmental concerns are less (not to say they are nonexistent) when the US does it because we tend to care about the environment more than china does, especially in california.

Also don't be decieved by the term, rare earth metals aren't really all that rare. If anything their expense comes from the difficulty in extracting them selectively from their ores - because rare earths are chemically similar (has to do with the f electron shell being physically "buried" under the d and s shells) they tend to ore together, and then become tricky to separate.