If I sell a product to a US citizen I have to pay US income tax despite not being in the US, my business not being in the US, and not creating the product in th

If I sell a product to a US citizen I have to pay US income tax despite not being in the US, my business not being in the US, and not creating the product in the US. I then have to hope the US has a tax treaty with my country in order to attempt to recoup the costs. Is that fair?