This figure shows the US reliance on imports for various minerals, from the US Geological Survey. I'm fully aware that minerals are not equally distributed around the world, and I'm a pro-trade guy, so I won't lose sleep tonight about these numbers. But during waking hours, I will wonder about whether the supplies from other countries are reasonably steady and reliable. I'll also wonder about whether global pollution is worse because US firms are importing minerals from countries with substantially lower environmental standards than the United States.