There's no telling exactly where the Trump administration's trade war is going as the president authorizes tariffs and then quickly suspends them, only to authorize them again and suspend them again or provide waivers for certain industries. While tariffs on narrowly defined categories of goods to guard against unfair competition may be workable, the administration's shotgun approach to tariffs risks a cutoff of strategic minerals that could strangle America's tech industry.
As I've written before, the United States is dangerously dependent on other countries for a wide-ranging list of metals and, in some cases, completely dependent. (For more on that, see here, here, here and here.) Responses to tariffs do not have to take the form of retaliatory tariffs by the targeted country. They can take the form of export restrictions that deny the United States key commodities and products necessary to important industries.
China currently controls 69 percent of rare earth elements (REE) mine production and almost 90 percent of the processing of these elements. REEs are a group of metals, often found in deposits together, that are critical for modern electronics (such as computer hard disks, smartphones, and cameras); strong magnets used in hybrid cars and wind turbines; X-ray and MRI scanning equipment; aircraft engines; and crude oil refining. This is just a partial list. There are no viable substitutes for these metals available at any scale that would be meaningful.