Tariffs are a tax on the exchange of goods between countries, largely paid for by American companies in this instance. In a world where free trade in North America has been a given for decades, many supply chains, particularly those for cars, involve goods moving across borders before a product is ready to be sold to American consumers.

The tariffs are targeting a rule that allows Chinese retailers like Shein and Temu to avoid paying duties on packages worth $800 or less.