China is threatening to use rare earths exports as a tool in its bitter trade fight with the United States. Thus far, the threat is more rhetorical than real, but it is an option if China wants to escalate the dispute. Doing so would strip China of an important diplomatic fig leaf and make clear to the world that Beijing is ready to fight without constraint when challenged.
Rare earths are a group of 17 metals used in a wide range of high technology products, from cellphones to cancer treatment drugs to automobile emissions systems. They are also vital to advanced weapons and other strategic systems, such as jet engines, lasers, night vision goggles and displays, and as a result have been designated as “critical” by the U.S. government.