[nyrath]

I was under the impression that the extraction and purification of rare earth elements was such an ecological catastrophe that environmental protection laws in the US had made the existing mines in the US so unprofitable that they shut down.

[46Bit]

It's a little more complex than that, but I'd say that's what it boils down to. There's all sorts of horrible stuff that gets mined along with the rare earths, much of it exceedingly hazardous.