The auto industry has been hit particularly hard by China's rare earth export restrictions, but analysts warn Western defense giants are also vulnerable.

The US trade war with China has a major sticking point: rare earths minerals. Last month, President Donald Trump said the United States needed Greenland “very badly,” renewing his threat to annex the Danish territory.

Chinese exports of rare earths, a group of 17 minerals at the center of a trade dispute with Washington, rose 23% in May from the previous month, according to customs data on Monday.