It’s worse than that. After they realized that they had no system to support their idiotic plan, they tried to make it every other country’s problem by requiring that the vendor making the sale (in the other country) collect the tax and remit it to the US before the package gets here. Previously, tariffs were collected in the US at the port of entry or on delivery for smaller packages, and the sender didn’t have to worry about collecting them. This change is what caused all of the foreign postal services to halt service to the US.

Yeah, I haven't seen enough coverage of this. Just edicts and no process and Customs is still reeling and never found their feet from the first time tariffs were imposed. There isn't even a remit process or guidelines if a foreign postal service tried to send the payments.