Say China cuts off exports of a strategic material like titanium. We are categorically screwed... period. The have more than a quarter of the world’s supply of titanium reserves. We have effectively zero. Chinese titanium is not in line to be slapped with a tariff that I am aware of... but the point is that there are so many strategic materials that the USA has no ability to harvest (lithium is another great example) that it is frankly moronic to get into fights with people who have things we need.