China’s Rare Earth Curbs Have ‘Changed Psychology’ at US Firms

China’s weaponization of rare earths in its trade war with the US will spark a much greater focus on American supply security for critical minerals, according to MP Materials Corp., the only US miner of the key materials used in smartphones and defense applications.

“Regardless of how trade negotiations evolve from here, the system as it existed is broken, and the rare-earth Humpty Dumpty, so to speak, is not getting put back together,” the miner’s Chief Executive Officer, Jim Litinsky, said on an earnings call last Friday.

China, which dominates global supply, put export restrictions on seven types ...