This may explain the China-Japan rare-earths standoff: Beijing is signaling more forcefully now that, if Japanese companies want broad access to rare earths, they should move to China, or buy their rare-earth components from Chinese companies.
There is also almost always thorium, a lightly radioactive metal, in the same ores, and it has to be disposed of. So ramping up production would mean that Western countries would need to tolerate a level of pollution they've been all too happy to outsource to China.