> but also strategic value, as China currently is the only source for some rare earths

China effectively subsidizes mining for strategic purposes. Cheaper mining = cheaper manufacturing = strong industrial base = higher employment and lots of foreign IP to acquire.

This blew up in their face for rare earths, because they are valuable enough that shipping isn't a big deal, so cheaper rare earths in China just means cheaper rare earths in Japan.

If they didn't subsidize mining, or they keep restricting exports, people will look elsewhere. I'm not sure if China has particularly good reserves, I think they just dig it up cheaper, because they want to feed their industrial base.