Shoppers got a little relief this week from a giant tariff on previously cheap, duty-free goods from China. But the tariffs that do remain are still poised to derail the shopping habits of millions of Americans who shop at ultra-low-priced e-commerce sites like Shein and Temu.

Monday's announcement of a temporary reduction in import tariffs is only the latest chapter in a nearly eight-year trade dispute that began during President Donald Trump's first term. The agreement, which followed discussions between American and Chinese representatives in Geneva,