What if I'm buying non-slaves from a foreign person? What if I tried to buy slaves from a non-foreign person? I'd argue the former is fine and the latter is st

What if I'm buying non-slaves from a foreign person? What if I tried to buy slaves from a non-foreign person? I'd argue the former is fine and the latter is still not fine. So international trade agreements are surplus to requirements, since basic decency is enforced anyway.