Why Rare Earths Could Give China a Trade War Cudgel

U.S. President Donald Trump’s threat to cut off the supply of chips and processors to Huawei Technologies Co. is hitting China’s biggest tech company where it hurts – its dependence on other nations for the semiconductors and software used in smartphones and networking gear. So when China’s President Xi Jinping showed up days later at a rare earths processing plant, many observers saw a message in the visit: the U.S. has its own tech vulnerabilities, too.

A group of 17 chemically related elements found in mineral form that have magnetic and optical properties useful for making electronics more efficient. Electric vehicle makers rely on them for lighter-weight battery and motor components. Neodymium and praseodymium combine to make powerful magnets used in aircraft, headphones and much more. Yttrium, a silvery metal, is used in cancer and rheumatoid arthritis drugs as well as color televisions and camera lenses. They’re also frequent components of everyday objects like light-emitting diodes, or LEDs, used to light up smartphones and stadium scoreboards.