[whyisthewhat]

Just as a point of clarification, Chinese have no obligation to comply with American sanctions, unless they’re using the American financial system.

[seanmcdirmid]

Right. You are free to trade with Iran, as long as you don't mind disconnecting from the US financial system. Or you try to set up a shell company that does the trades but keeps the parent company from violating the sanctions (to be fair, Chinese companies learned how to do this from American companies).